In situ fabrication of atomically adjacent dual-vacancy sites for nearly 100% selective CH4 production.

The photocatalytic CO2-to-CH4 conversion involves multiple consecutive proton-electron coupling transfer processes. Achieving high CH4 selectivity with satisfactory conversion efficiency remains challenging since the inefficient proton and electron delivery path results in sluggish proton-electron transfer kinetics. Herein, we propose the fabrication of atomically adjacent anion-cation vacancy as paired redox active sites that could maximally promote the proton- and electron-donating efficiency to simultaneously enhance the oxidation and reduction half-reactions, achieving higher photocatalytic CO2 reduction activity and CH4 selectivity. Taking TiO2 as a photocatalyst prototype, the operando electron paramagnetic resonance spectra, quasi in situ X-ray photoelectron spectroscopy measurements, and high-angle annular dark-field-scanning transmission electron microscopy image analysis prove that the VTi on TiO2 as initial sites can induce electron redistribution and facilitate the escape of the adjacent oxygen atom, thereby triggering the dynamic creation of atomically adjacent dual-vacancy sites during photocatalytic reactions. The dual-vacancy sites not only promote the proton- and electron-donating efficiency for CO2 activation and protonation but also modulate the coordination modes of surface-bound intermediate species, thus converting the endoergic protonation step to an exoergic reaction process and steering the CO2 reduction pathway toward CH4 production. As a result, these in situ created dual active sites enable nearly 100% CH4 selectivity and evolution rate of 19.4 µmol g-1 h-1, about 80 times higher than that of pristine TiO2. Thus, these insights into vacancy dynamics and structure-function relationship are valuable to atomic understanding and catalyst design for achieving highly selective catalysis.

Resolving the overlooked photochemical nitrophenol transformation mechanism induced by nonradical species under visible light.

Nitrophenols present on the surface of particulates are ubiquitous in the atmosphere. However, its atmospheric photochemical transformation pathway remains unknown, for which the crucial effect of visible light is largely overlooked, resulting in an incomplete understanding of the effects of nitrophenols in the atmospheric environment. This study delves into the photolysis mechanism of 4-nitrophenol (4NP), one of the most abundant atmospheric nitrophenol compounds, on the surface of photoactive particulates under visible light irradiation. Unexpectedly, the nonradical species (singlet oxygen, 1O2) was identified as a dominant factor in driving the visible photolysis of 4NP. The pathways of HONO and p-benzoquinone (C6H4O2) generation were clarified by acquiring direct evidence of C-N and O-H bond breakage in the nitro (-NO2) and hydroxyl (-OH) groups of 4NP. The further decomposition of HONO results in the generation of NO and hydroxyl radicals, which could directly contribute to atmospheric oxidizing capacity and complicate the PM2.5 composition. Significantly, the behavior of 1O2-induced visible photolysis of 4NP was universal on the surface of common particulates in the atmosphere, such as A1 dust and Fe2O3. This work advances the understanding of the photochemical transformation mechanism of particulate-phase atmospheric nitrophenols, which is indispensable in elucidating the role of nitrophenols in atmospheric chemistry.

Boosting exciton dissociation and charge transfer in CsPbBr3 QDs via ferrocene derivative ligation for CO2 photoreduction.

Photo-catalytic CO2 reduction with perovskite quantum dots (QDs) shows potential for solar energy storage, but it encounters challenges due to the intricate multi-electron photoreduction processes and thermodynamic and kinetic obstacles associated with them. This study aimed to improve photo-catalytic performance by addressing surface barriers and utilizing multiple-exciton generation in perovskite QDs. A facile surface engineering method was employed, involving the grafting of ferrocene carboxylic acid (FCA) onto CsPbBr3 (CPB) QDs, to overcome limitations arising from restricted multiple-exciton dissociation and inefficient charge transfer dynamics. Kelvin Probe Force Microscopy and XPS spectral confirmed successfully creating an FCA-modulated microelectric field through the Cs active site, thus facilitating electron transfer, disrupting surface barrier energy, and promoting multi-exciton dissociations. Transient absorption spectroscopy showed enhanced charge transfer and reduced energy barriers, resulting in an impressive CO2-to-CO conversion rate of 132.8 µmol g-1 h-1 with 96.5% selectivity. The CPB-FCA catalyst exhibited four-cycle reusability and 72 h of long-term stability, marking a significant nine-fold improvement compared to pristine CPB (14.4 µmol g-1 h-1). These results provide insights into the influential role of FCA in regulating intramolecular charge transfer, enhancing multi-exciton dissociation, and improving CO2 photoreduction on CPB QDs. Furthermore, these findings offer valuable knowledge for controlling quantum-confined exciton dissociation to enhance CO2 photocatalysis.

Dissecting the Photochemical Reactivity of Metal Ions during Atmospheric Nitrate Transformations on Photoactive Mineral Dust.

Dissecting the photochemical reactivity of metal ions is a significant contribution to understanding secondary pollutant formation, as they have a role to be reckoned with atmospheric chemistry. However, their photochemical reactivity has received limited attention within the active nitrogen cycle, particularly at the gas-solid interface. In this study, we delve into the contribution of magnesium ion (Mg2+) and ferric ion (Fe3+) to nitrate decomposition on the surface of photoactive mineral dust. Under simulated sunlight irradiation, the observed NOX production rate differs by an order of magnitude in the presence of Mg2+ (6.02 × 10-10 mol s-1) and Fe3+ (2.07 × 10-11 mol s-1). The markedly decreased fluorescence lifetime induced by Mg2+ and the change in the valence of Fe3+ revealed that Mg2+ and Fe3+ significantly affect the concentration of nitrate decomposition products by distinct photochemical reactivity with photogenerated electrons. Mg2+ promotes NOX production by accelerating charge transfer, while Fe3+ hinders nitrate decomposition by engaging in a redox cyclic reaction with Fe2+ to consume photogenerated carriers continuously. Furthermore, when Fe3+ coexists with other metal ions (e.g., Mg2+, Ca2+, Na+, and K+) and surpasses a proportion of approximately 12%, the photochemical reactivity of Fe3+ tends to be dominant in depleting photogenerated electrons and suppressing nitrate decomposition. Conversely, below this threshold, the released NOX concentration increases sharply as the proportion of Fe3+ decreases. This research offers valuable insights into the role of metal ions in nitrate transformation and the generation of reactive nitrogen species, contributing to a deep understanding of atmospheric photochemical reactions.

Insight into the Overlooked Photochemical Decomposition of Atmospheric Surface Nitrates Triggered by Visible Light.

The nitrogen oxides (NOx) formed by photochemical reaction of surface nitrates raise significant concerns. However, little is known about the effect of visible light (>380 nm) on nitrate decomposition and the reaction mechanism. Herein, the decomposition of surface nitrates is investigated under visible light. The results indicate that visible light photocatalysis contributes significantly to nitrate decomposition. Monodentate nitrate (m-NO3 - ) can be decomposed into NOx by photogenerated electrons starting from the weakly coordinated N-O bond. Water vapor promotes NOx generation because more stable bidentate nitrate (b-NO3 - ) will be converted into m-NO3 - by surface hydroxyl groups through hydrogen bonding interactions. Alternatively, b-NO3 - can be directly decomposed to NO2 - by NO attack, but this process is subject to photocatalytic oxidation. This work brings a new focus on the atmospheric NOx sources and provides a more nuanced understanding of nitrates decomposition processes.

Efficient visible light photocatalytic NO abatement over SrSn(OH)6 nanowires loaded with Ag/Ag2O cocatalyst.

SrSn(OH)6 (SSOH) possesses a high oxidation potential in the valence band (VB), which is suitable for photocatalytic oxidation removal of pollutants. However, the electrons in the VB of these catalysts are difficult to transition to the conduction band (CB) under visible light, which makes it difficult to utilize sunlight effectively. In this work, Ag/Ag2O is loaded on the surface of SSOH nanowires, which stimulates the interfacial charge-transfer transition on SSOH. Compared with pure-phase SSOH, the NO abatement ratio of Ag/Ag2O-SSOH under visible light irradiation is increased to 45.10%. The e- in the VB of Ag2O are excited into the CB under visible light, and are further transferred to the Ag to react with O2 to produce superoxide radicals. The photo-excited e- in the VB of SSOH enter into the VB of Ag2O through interfacial charge-transfer transition to recombine with the photo-generated holes in the VB of Ag2O, thereby leaving photo-generated holes in the VB of SSOH. The holes in the VB of SSOH have sufficient oxidizing ability to oxidize the adsorbed hydroxyl groups into hydroxyl radicals. This work provides a new perspective for photocatalytic removal of pollutants by wide band gap photocatalyst under visible light.

Unraveling the Mechanisms of Visible Light Photocatalytic NO Purification on Earth-Abundant Insulator-Based Core-Shell Heterojunctions.

Earth-abundant insulators are seldom exploited as photocatalysts. In this work, we constructed a novel family of insulator-based heterojunctions and demonstrated their promising applications in photocatalytic NO purification, even under visible light irradiation. The heterojunction formed between the insulator SrCO3 and the photosensitizer BiOI, via a special SrCO3-BiOI core-shell structure, exhibits an enhanced visible light absorbance between 400-600 nm, and an unprecedentedly high photocatalytic NO removal performance. Further density functional theory (DFT) calculations and X-ray photoelectron spectroscopy (XPS) analysis revealed that the covalent interaction between the O 2p orbital of the insulator (SrCO3, n-type) and the Bi 6p orbital of photosensitizer (BiOI, p-type) can provide an electron transfer channel between SrCO3 and BiOI, allowing the transfer of the photoexcited electrons from the photosensitizer to the conduction band of insulator (confirmed by charge difference distribution analysis and time-resolved fluorescence spectroscopy). The •O2- and •OH radicals are the main reactive species in photocatalytic NO oxidation. A reaction pathway study based on both in situ FT-IR and molecular-level simulation of NO adsorption and transformation indicates that this heterojunction can efficiently transform NO to harmless nitrate products via the NO → NO+ and NO2+ → nitrate or nitrite routes. This work provides numerous opportunities to explore earth-abundant insulators as visible-light-driven photocatalysts, and also offers a new mechanistic understanding of the role of gas-phase photocatalysis in controlling air pollution.

Highly Efficient Performance and Conversion Pathway of Photocatalytic NO Oxidation on SrO-Clusters@Amorphous Carbon Nitride.

This work demonstrates the first molecular-level conversion pathway of NO oxidation over a novel SrO-clusters@amorphous carbon nitride (SCO-ACN) photocatalyst, which is synthesized via copyrolysis of urea and SrCO3. The inclusion of SrCO3 is crucial in the formation of the amorphous carbon nitride (ACN) and SrO clusters by attacking the intralayer hydrogen bonds at the edge sites of graphitic carbon nitride (CN). The amorphous nature of ACN can promote the transportation, migration, and transformation of charge carriers on SCO-ACN. And the SrO clusters are identified as the newly formed active centers to facilitate the activation of NO via the formation of Sr-NOδ(+), which essentially promotes the conversion of NO to the final products. The combined effects of the amorphous structure and SrO clusters impart outstanding photocatalytic NO removal efficiency to the SCO-ACN under visible-light irradiation. To reveal the photocatalytic mechanism, the adsorption and photocatalytic oxidation of NO over CN and SCO-ACN are analyzed by in situ DRIFTS, and the intermediates and conversion pathways are elucidated and compared. This work presents a novel in situ DRIFTS-based strategy to explore the photocatalytic reaction pathway of NO oxidation, which is quite beneficial to understand the mechanism underlying the photocatalytic reaction and advance the development of photocatalytic technology for environmental remediation.

An Advanced Semimetal-Organic Bi Spheres-g-C3N4 Nanohybrid with SPR-Enhanced Visible-Light Photocatalytic Performance for NO Purification.

To achieve efficient photocatalytic air purification, we constructed an advanced semimetal-organic Bi spheres-g-C3N4 nanohybrid through the in-situ growth of Bi nanospheres on g-C3N4 nanosheets. This Bi-g-C3N4 compound exhibited an exceptionally high and stable visible-light photocatalytic performance for NO removal due to the surface plasmon resonance (SPR) endowed by Bi metal. The SPR property of Bi could conspicuously enhance the visible-light harvesting and the charge separation. The electromagnetic field distribution of Bi spheres involving SPR effect was simulated and reaches its maximum in close proximity to the Bi particle surface. When the Bi metal content was controlled at 25%, the corresponding Bi-g-C3N4 displayed outstanding photocatalytic capability and transcended those of other visible-light photocatalysts. The Bi-g-C3N4 exhibited a high structural stability under repeated photocatalytic runs. A new visible-light-induced SPR-based photocatalysis mechanism with Bi-g-C3N4 was proposed on the basis of the DMPO-ESR spin-trapping. The photoinduced electrons could transfer from g-C3N4 to the Bi metal, as revealed with time-resolved fluorescence spectra. The function of Bi semimetal as a plasmonic cocatalyst for boosting visible light photocatalysis was similar to that of noble metals, which demonstrated a great potential of utilizing the economically feasible Bi element as a substitute for noble metals for the advancement of photocatalysis efficiency.

Mechanism of visible light photocatalytic NO(x) oxidation with plasmonic Bi cocatalyst-enhanced (BiO)2CO3 hierarchical microspheres.

Semimetal bismuth (Bi), as an emerging non-noble metal-based cocatalyst and plasmonic photocatalyst, has attracted significant attention. In this work, a one-pot solvent-controlled synthesis strategy was utilized for the in situ-deposition of plasmonic Bi nanoparticles onto the surfaces of (BiO)2CO3 microspheres (BOC-WE) using bismuth citrate, sodium carbonate, and ethylene glycol as precursors. The introduction of the Bi nanoparticles has a pivotal effect on the morphology, optical and photocatalytic performance of the pristine (BiO)2CO3. The results indicated that the Bi nanoparticles were generated on the surface of (BiO)2CO3 microspheres via the in situ reduction of Bi(3+) by ethylene glycol. The Bi-deposited (BiO)2CO3 microspheres were used for the photocatalytic purification of NOx in air under visible light irradiation. Significantly, the BOC-WE samples exhibited a drastically promoted photocatalytic performance with a NOx removal ratio (η) of 37.2%, superior to pristine (BiO)2CO3 (η = 19.1%), outperforming other well-known visible light photocatalysts, such as C-doped TiO2 (η = 21.8%), BiOBr (η = 21.3%), BiOI (η = 14.9%) and C3N4 (η = 25.5%). The conspicuously enhanced photocatalytic capability can be attributed to the synergistic effects of the surface plasmon resonance (SPR) effect, increased visible light absorption and the efficient separation of electron-hole pairs induced by the Bi nanoparticles. The Bi nanoparticles can act as a non-noble metal-based cocatalyst for strengthening photocatalytic performance, which is similar to the behavior of noble metals (Au, Ag) in enhancing photocatalysis. The mechanism of visible light photocatalytic NOx oxidation was investigated. DMPO-ESR spin-trapping results demonstrated that hydroxyl radicals were confirmed to be the main active species for NOx photo-oxidation. Due to the SPR effect of Bi, the BOC-WE could produce more hydroxyl radicals than BOC, which was responsible for the enhanced NO photo-oxidation ability. Moreover, the BOC-WE photocatalysts showed high photochemical stability under repeated irradiation. This work demonstrates the feasibility of utilizing low cost Bi cocatalysts as a substitute for noble metals to enhance the performance of other photocatalysts. This work could not only provide new insights into the in situ fabrication of Bi/semiconductor nanocomposites, but also pave a new way for the modification of photocatalysts with non-noble metals as cocatalysts to achieve an enhanced performance for environmental and energetic applications.

Hypoxia-induced cytosolic calcium influx is mediated primarily by the reverse mode of Na+/Ca2+ exchanger in smooth muscle cells of fetal small pulmonary arteries.

AIM: Constriction of small pulmonary arteries and high resistance of pulmonary circulation are important for maintaining fetal circulation before birth. In this study, we investigated how cytosolic free calcium concentration ([Ca(2+)]i) in fetal lamb small pulmonary artery smooth muscle cells (SPASMC) was affected by hypoxia and regulated by calcium pumps during this process. METHODS: (Ca(2+))i in response to acute hypoxia was determined spectrofluorometrically with fluo-3AM in cultured fetal SPASMC. Chemicals or solutions, including ryanodine, 2-aminoethoxydiphenyl borate, Ca(2+)-free solution with 20 mmol ethyleneglycoltetraacetic (EGTA), nimodipine, Na(+)-free medium and KB-R7943, were administrated at the same time point when samples were exposed to acute hypoxia. RESULTS: (Ca(2+))i in fetal lamb SPASMC increased under acute hypoxia. 2-Aminoethoxydiphenyl borate, an inhibitor of inositol triphosphate calcium store, partially attenuated the (Ca(2+))i increase after 6-min treatment. Ryanodine, an inhibitor of ryanodine-sensitive calcium stores, had no effect on the (Ca(2+))i increase. Ca(2+)-free solution with EGTA completely abolished this increase. Both nimodipine, that blocks the voltage-gated calcium channel, and KB-R7943, that inhibits the reverse mode of Na(+)/Ca(2+) exchanger, greatly diminished the hypoxia-induced (Ca(2+))i increase. The inhibitory effect of KB-R7943 was stronger than nimodipine, evidenced by the fact that (Ca(2+))i dropped near to the baseline level in the presence of KB-R7943 at a later time point. Low extracellular Na(+) concentration enhanced the hypoxia-induced increase of (Ca(2+))i. CONCLUSION: These results suggest that hypoxia-induced Ca(2+) increase in fetal SPASMC results from cytosolic Ca(2+) influx mediated primarily by the reverse mode of Na(+)/Ca(2+) exchanger.

Mechanism of Interfacial Molecular Interactions Reveals the Intrinsic Factors for the Highly Enhanced Sensing Performance of Ag-Loaded Co3O4.

The noble metal-loaded strategy can effectively improve the gas-sensing performances of metal oxide sensors. However, the gas-solid interfacial interactions between noble metal-loaded sensing materials and gaseous species remain unclear, posing a significant challenge in correlating the physical and chemical processes during gas sensing. In this study, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and in situ Raman spectroscopy were conducted to collaboratively investigate the interfacial interactions involved in the ethanol gas-sensing processes over Co3O4 and Ag-loaded Co3O4 sensors. In situ DRIFTS revealed differences in the compositions and quantities of sensing reaction products, as well as in the adsorption-desorption interactions of surface species, among Co3O4 and Ag-loaded Co3O4 materials. In parallel, in situ Raman spectroscopy demonstrated that the ethanol atmosphere can modulate the electron scattering of Ag-loaded Co3O4 materials but not of raw Co3O4. In situ experimental results revealed the intrinsic reason for the highly enhanced sensing performances of the Ag-loaded Co3O4 sensors toward ethanol gas, including a decreased optimal working temperature (from 250 to 150 °C), an improved gas response level (from 24 to 257), and accelerated gas recovery dynamics. This work provides an effective platform to investigate the interfacial interactions of sensing processes at the molecular level and further advances the development of high-performance gas sensors.

Ligand-mediated exciton dissociation and interparticle energy transfer on CsPbBr3 perovskite quantum dots for efficient CO2-to-CO photoreduction.

Perovskite quantum dots (PQDs) hold immense potential as photocatalysts for CO2 reduction due to their remarkable quantum properties, which facilitates the generation of multiple excitons, providing the necessary high-energy electrons for CO2 photoreduction. However, harnessing multi-excitons in PQDs for superior photocatalysis remains challenging, as achieving the concurrent dissociation of excitons and interparticle energy transfer proves elusive. This study introduces a ligand density-controlled strategy to enhance both exciton dissociation and interparticle energy transfer in CsPbBr3 PQDs. Optimized CsPbBr3 PQDs with the regulated ligand density exhibit efficient photocatalytic conversion of CO2 to CO, achieving a 2.26-fold improvement over unoptimized counterparts while maintaining chemical integrity. Multiple analytical techniques, including Kelvin probe force microscopy, temperature-dependent photoluminescence, femtosecond transient absorption spectroscopy, and density functional theory calculations, collectively affirm that the proper ligand termination promotes the charge separation and the interparticle transfer through ligand-mediated interfacial electron coupling and electronic interactions. This work reveals ligand density-dependent variations in the gas-solid photocatalytic CO2 reduction performance of CsPbBr3 PQDs, underscoring the importance of ligand engineering for enhancing quantum dot photocatalysis.

Rapid Energy Exchange between In Situ Formed Bromine Vacancies and CO2 Molecules Enhances CO2 Photoreduction.

Photocatalytic reduction of CO2 into fuels provides a prospective tactic for regulating the global carbon balance utilizing renewable solar energy. However, CO2 molecules are difficult to activate and reduce due to the thermodynamic stability and chemical inertness. In this work, we develop a novel strategy to promote the adsorption and activation of CO2 molecules via the rapid energy exchange between the photoinduced Br vacancies and CO2 molecules. Combining in situ continuous wave-electron paramagnetic resonance (cw-EPR) and pulsed EPR technologies, we observe that the spin-spin relaxation time (T2) of BiOBr is decreased by 198 ns during the CO2 photoreduction reaction, which is further confirmed by the broadened EPR linewidth. This result reveals that there is an energy exchange interaction between in situ formed Br vacancies and CO2 molecules, which promotes the formation of high-energy CO2 molecules to facilitate the subsequent reduction reaction. In addition, theoretical calculations indicate that the bended CO2 adsorption configuration on the surface of BiOBr with Br vacancies caused the decrease of the lowest unoccupied molecular orbital of the CO2 molecule, which makes it easier for CO2 molecules to acquire electrons and get activated. In situ diffuse reflectance infrared Fourier transform spectroscopy further shows that the activated CO2 molecules are favorably converted to key intermediates of COOH*, resulting in a CO generation rate of 9.1 µmol g-1 h-1 and a selectivity of 100%. This study elucidates the underlying mechanism of CO2 activation at active sites and deepens the understanding of CO2 photoreduction reaction.

Amorphous SnO2 decorated ZnSn(OH)6 promotes interfacial hydroxyl polarization for deep photocatalytic toluene mineralization.

Surface hydroxyl groups play a decisive role in the generation of hydroxyl radicals with stronger oxidizing ability, which is indispensable in photocatalytic VOCs removal, especially under the condition of low humidity. In this work, non-noble amorphous SnO2 decorated ZnSn(OH)6 (ZSH) was synthesized by an in-situ method. The charge transport, reactant activation and hydroxyl polarization are enhanced through decoration of amorphous SnO2 on ZSH. Combined with the designed experiment, in-situ EPR, DTF calculation and in-situ DRIFTS, the role and mechanism of interfacial hydroxyl polarization are revealed on SnO2 decorated ZnSn(OH)6. Compared with pristine ZSH and noble-metal modified ZSH, the toluene degradation rate of amorphous SnO2 decorated ZSH is increased by 13.0 and 3.8 times, and the toluene mineralization rate is increased by 5.2 and 2.2 times. The ZSH-24 sample maintains a high toluene degradation activity after 6 cyclic utilization without catalyst deactivation. This work emphasizes the role of non-noble metal and the origin of hydroxyl group polarization on ZnSn(OH)6 for photocatalytic VOCs mineralization.

Promote hydroxyl radical and key intermediates formation for deep toluene mineralization via unique electron transfer channel.

The degradation and mineralization of volatile organic compounds (VOCs) in gas-solid phase photocatalytic systems suffer great challenges due to the low electron transfer efficiency and slow benzene ring-opening kinetics. Hence, a heterojunction photocatalyst of Bi2SiO5/TiO2 has been synthesized by a facile method. Bi2SiO5/TiO2 shows the ability of mineralizing toluene to CO2 with a degradation rate of 85.5%, while TiO2 is 49.0% and presents a continuous deactivation. Experimental characterizations and theoretical calculations indicate that a unique electron transfer channel of Bi/Si-O-Ti can be established in the heterojunction sample due to the coupling of the interface. The channel facilitates electron transfer to the catalyst surface, generating •OH radicals with strong oxidation and ring-opening ability. Moreover, in-situ DRIFTS reveal that the selective generation of benzoic acid on Bi2SiO5/TiO2 heterojunction plays a critical role in the ring-opening of toluene. This work discloses a novel paradigm to obtain the deep and durable photocatalytic mineralization of toluene.

Novel in situ N-doped (BiO)2CO3 hierarchical microspheres self-assembled by nanosheets as efficient and durable visible light driven photocatalyst.

Novel N-doped (BiO)(2)CO(3) hierarchical microspheres (N-BOC) were fabricated by a facile one-pot template free method on the basis of hydrothermal treatment of bismuth citrate and urea in water for the first time. The N-BOC sample was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, N(2) adsorption-desorption isotherms, and Fourier transform-infrared spectroscopy. The N-BOC was constructed by the self-assembly of single-crystalline nanosheets. The aggregation of nanosheets led to the formation of hierarchical framework with mesopores, which is favorable for efficient transport of reaction molecules and harvesting of photoenergy. Due to the in situ doped nitrogen substituting for oxygen in the lattice of (BiO)(2)CO(3), the band gap of N-BOC was reduced from 3.4 to 2.5 eV, making N-BOC visible light active. The N-BOC exhibited not only excellent visible light photocatalytic activity, but also high photochemical stability and durability during repeated and long-term photocatalytic removal of NO in air due to the special hierarchical structure. This work demonstrates that the facile fabrication method for N-BOC combined with the associated outstanding visible light photocatalytic performance could provide new insights into the morphology-controlled fabrication of nanostructured photocatalytic materials for environmental pollution control.

[Surgical repair of truncus arteriosus in children: early results and long-term outcomes].

OBJECTIVE: To recite early results and long-term outcomes after surgical repair of persistent truncus arteriosus (PTA). METHODS: The clinic data of 54 patients underwent surgical repair for PTA from January 1999 to December 2009 was analyzed retrospectively. There were 36 male and 18 female patients, with a mean age of (9 ± 10) months (range, 1 to 38 months; median, 5 months). Preoperative mechanical ventilation was required in 5 patients. The surgical procedures were closure of ventricular septal defect and re-establishment of continuity between right ventricle and pulmonary artery. The right ventricular outflow tract (RVOT) was reconstructed by direct anastomosis pulmonary artery to right ventriculotomy with anterior wall patch enlargement (28 cases), or by inserting conduits (26 cases). Valvuloplasty were performed in 4 patients with truncal valves moderate to severe insufficiency and aortoplasty in 3 patients with interrupted aortic arch (IAA). RESULTS: There were 3 patients (5.6%) died of pulmonary hypertensive crisis in hospital. The mean duration of ventilation was 6.8 days in 5 patients who were intubated before operation, while the others were 3.6 days. Forty-seven (92.2%) patients were followed-up for mean (6.8 ± 2.5) years (from 2.5 to 11.0 years). There were 2 patients with mild to moderate aortic regurgitation. One patient with aortic arch obstruction underwent balloon dilatation 2 years postoperatively. Among those patients who underwent direct anastomoses, 8 (32.0%) patients had pulmonary branch stenosis at 7 months to 1.5 years postoperatively, 12 (48.0%) patients were freedom from surgical reintervention 5.0 to 11.0 years postoperatively. Among those inserting conduits, 7 patients (31.8%) had conduit stenosis at 2.8 to 7.0 years after operation. Reoperations were performed for RVOT in 15 patients and there was no mortality. CONCLUSIONS: It is difficult to treat the PTA patients with IAA, intra-mural coronary artery or mechanical ventilation support before operation. The technique of direct anastomosis between pulmonary artery and right ventricle offers the potential growth for RVOT, but bilateral pulmonary branch stenosis may be occurred at earlier period of postoperation in some patients.

Substitution of B-site in BaSb2O6 perovskite for surface lattice oxygen activation and boosted photocatalytic toluene mineralization.

Perovskite oxides possess significant prospects in environment application because of their compositional versatility and controllable band structure for redox reactions. Nevertheless, low charge separation and limited reactants activation restrict their performance for practical applications. In this work, we reveal that the electronic structure of BaSb2O6 can be modulated effectively by substituting B-site cations, leading to broadened light response range and promoted carrier separation. The Ga atoms substitute the Sb atoms to form GaO bonds and enable octahedral distortion, resulting in the electron transfer from Ga atom to O atoms and realizing lattice oxygen activation. The unique electronic localization in the BaSb2O6 surface facilitates the adsorption and activation of O2, H2O, toluene and reaction intermediates, thus enhancing ROS generation for toluene mineralization. Compared with the performance of pure BaSb2O6, the photocatalytic toluene degradation and mineralization of 5 wt% Ga-BaSb2O6 are increased by 4.5 times and 4.8 times without obvious deactivation. The reported facile and valid strategy for in situ controlling of B-site in perovskite and their unique effects on the electronic structure would benefit the development of high-performance perovskites for environmental applications.

Differential Diagnosis Value of Shear-Wave Elastography for Superficial Enlarged Lymph Nodes.

Objectives: To evaluate the diagnostic efficiency and diagnostic threshold of conventional US and shear-wave elastography (SWE) in superficial enlarged lymph nodes (LNs). Methods: A total of 204 patients with superficial enlarged LNs were enrolled in this retrospective study aged 46.0 ± 15.2 years from March 2020 to March 2021. LNs with a long axis larger than 0.7 cm were considered as superficial enlarged. Before the histological biopsy, LNs that were considered suspicious according to both conventional US and SWE were included, while LNs with no or unclear pathological results, or with no satisfactory SWE images, were excluded. The conventional and 2-D SWE examinations were performed with Aplio i800 and Acuson sequoia equipped with i18LX5 linear-array transducer (5-18 MHz) and 10L4 linear-array transducer (4-10 MHz), respectively. Both E Median and Vs Median parameters were investigated by two senior ultrasound physicians. The pathological results were performed as the gold standard. Results: Variables including transverse axis size, lymphatic hilum, L/T ratio, echogenicity, and color Doppler pattern were considered significant. The mean E Median value in benign, metastatic LNs, and lymphoma were 28.26 ± 8.87 kPa, 77.46 ± 22.85 kPa, and 50.37 ± 5.41 kPa (p <0.001), while Vs Median values were 3.02 ± 0.50 m/s, 4.87 ± 0.90 m/s, and 4.09 ± 0.22 m/s, respectively (p < 0.001). The diagnostic performance indicated the high sensitivity, specificity, PPV, NPV, and overall accuracy of conventional US combined with SWE. The optimal cutoff values of E Median and Vs Median for predicting malignant LNs were 42.90 kPa and 3.73 m/s, respectively. As AUC value, sensitivity, specificity, accuracy, PPV, and NPV revealed, the indexes of E Median were 0.976, 0.927, 0.975, 0.946, 0.983, and 0.897, respectively, while Vs Median were 0.970, 0.927, 0.963, 0.941, 0.975, and 0.895, respectively (p <0.001). The ROC curves of both E Median (AUC=0.976) Vs Median (AUC=0.970) suggested the remarkable diagnostic efficiency in distinguishing benignity between suspected malignant LNs. Conclusions: Above results indicated that conventional US together with 2-D SWE could elevate the diagnostic performance. Meanwhile, the parameters of 2-D SWE including E Median and Vs Median could effectively assess malignant LNs, which provide valuable differentiating information in superficial enlarged LNs.