Hydroxyl-Bonded Co Single Atom Site on Boroncarbonitride Surface Realizes Nonsacrificial H2O2 Synthesis in the Near-Infrared Region.

Photocatalytic synthesis of hydrogen peroxide (H2O2) from O2 and H2O under near-infrared light is a sustainable renewable energy production strategy, but challenging reaction. The bottleneck of this reaction lies in the regulation of O2 reduction path by photocatalyst. Herein, the center of the one-step two-electron reduction (OSR) pathway of O2 for H2O2 evolution via the formation of the hydroxyl-bonded Co single-atom sites on boroncarbonitride surface (BCN-OH2/Co1) is constructed. The experimental and theoretical prediction results confirm that the hydroxyl group on the surface and the electronic band structure of BCN-OH2/Co1 are the key factor in regulating the O2 reduction pathway. In addition, the hydroxyl-bonded Co single-atom sites can further enrich O2 molecules with more electrons, which can avoid the one-electron reduction of O2 to •O2 -, thus promoting the direct two-electron activation hydrogenation of O2. Consequently, BCN-OH2/Co1 exhibits a high H2O2 evolution apparent quantum efficiency of 0.8% at 850 nm, better than most of the previously reported photocatalysts. This study reveals an important reaction pathway for the generation of H2O2, emphasizing that precise control of the active site structure of the photocatalyst is essential for achieving efficient conversion of solar-to-chemical.

Efficient ammonia synthesis from the air using tandem non-thermal plasma and electrocatalysis at ambient conditions.

While electrochemical N2 reduction presents a sustainable approach to NH3 synthesis, addressing the emission- and energy-intensive limitations of the Haber-Bosch process, it grapples with challenges in N2 activation and competing with pronounced hydrogen evolution reaction. Here we present a tandem air-NOx-NOx--NH3 system that combines non-thermal plasma-enabled N2 oxidation with Ni(OH)x/Cu-catalyzed electrochemical NOx- reduction. It delivers a high NH3 yield rate of 3 mmol h-1 cm-2 and a corresponding Faradaic efficiency of 92% at -0.25 V versus reversible hydrogen electrode in batch experiments, outperforming previously reported ones. Furthermore, in a flow mode concurrently operating the non-thermal plasma and the NOx- electrolyzer, a stable NH3 yield rate of approximately 1.25 mmol h-1 cm-2 is sustained over 100 h using pure air as the intake. Mechanistic studies indicate that amorphous Ni(OH)x on Cu interacts with hydrated K+ in the double layer through noncovalent interactions and accelerates the activation of water, enriching adsorbed hydrogen species that can readily react with N-containing intermediates. In situ spectroscopies and density functional theory (DFT) results reveal that NOx- adsorption and their hydrogenation process are optimized over the Ni(OH)x/Cu surface. This work provides new insights into electricity-driven distributed NH3 production using natural air at ambient conditions.

Ruthenium Single Atomic Sites Surrounding the Support Pit with Exceptional Photocatalytic Activity.

Single-metal atomic sites and vacancies can accelerate the transfer of photogenerated electrons and enhance photocatalytic performance in photocatalysis. In this study, a series of nickel hydroxide nanoboards (Ni(OH)x NBs) with different loadings of single-atomic Ru sites (w-SA-Ru/Ni(OH)x) were synthesized via a photoreduction strategy. In such catalysts, single-atomic Ru sites are anchored to the vacancies surrounding the pits. Notably, the SA-Ru/Ni(OH)x with 0.60 wt % Ru loading (0.60-SA-Ru/Ni(OH)x) exhibits the highest catalytic performance (27.6 mmol g-1 h-1) during the photocatalytic reduction of CO2 (CO2RR). Either superfluous (0.64 wt %, 18.9 mmol g-1 h-1; 3.35 wt %, 9.4 mmol-1 h-1) or scarce (0.06 wt %, 15.8 mmol g-1 h-1; 0.29 wt %, 21.95 mmol g-1 h-1; 0.58 wt %, 23.4 mmol g-1 h-1) of Ru sites have negative effect on its catalytic properties. Density functional theory (DFT) calculations combined with experimental results revealed that CO2 can be adsorbed in the pits; single-atomic Ru sites can help with the conversion of as-adsorbed CO2 and lower the energy of *COOH formation accelerating the reaction; the excessive single-atomic Ru sites occupy vacancies that retard the completion of CO2RR.

Selective CO2 Reduction to Ethylene Mediated by Adaptive Small-molecule Engineering of Copper-based Electrocatalysts.

Electrochemical CO2 reduction reaction (CO2 RR) over Cu catalysts exhibits enormous potential for efficiently converting CO2 to ethylene (C2 H4 ). However, achieving high C2 H4 selectivity remains a considerable challenge due to the propensity of Cu catalysts to undergo structural reconstruction during CO2 RR. Herein, we report an in situ molecule modification strategy that involves tannic acid (TA) molecules adaptive regulating the reconstruction of a Cu-based material to a pathway that facilitates CO2 reduction to C2 H4 products. An excellent Faraday efficiency (FE) of 63.6 % on C2 H4 with a current density of 497.2 mA cm-2 in flow cell was achieved, about 6.5 times higher than the pristine Cu catalyst which mainly produce CH4 . The in situ X-ray absorption spectroscopy and Raman studies reveal that the hydroxyl group in TA stabilizes Cuδ+ during the CO2 RR. Furthermore, theoretical calculations demonstrate that the Cuδ+ /Cu0 interfaces lower the activation energy barrier for *CO dimerization, and hydroxyl species stabilize the *COH intermediate via hydrogen bonding, thereby promoting C2 H4 production. Such molecule engineering modulated electronic structure provides a promising strategy to achieve highly selective CO2 reduction to value-added chemicals.

Spatial Position Regulation of Cu Single Atom Site Realizes Efficient Nanozyme Photocatalytic Bactericidal Activity.

Recently, single-atom nanozymes have made significant progress in the fields of sterilization and treatment, but their catalytic performance as substitutes for natural enzymes and drugs is far from satisfactory. Here, a method is reported to improve enzyme activity by adjusting the spatial position of a single-atom site on the nanoplatforms. Two types of Cu single-atom site nanozymes are synthesized in the interlayer (CuL /PHI) and in-plane (CuP /PHI) of poly (heptazine imide) (PHI) through different synthesis pathways. Experimental and theoretical analysis indicates that the interlayer position of PHI can effectively adjust the coordination number, coordination bond length, and electronic structure of Cu single atoms compared to the in-plane position, thereby promoting photoinduced electron migration and O2 activation, enabling effective generate reactive oxygen species (ROS). Under visible light irradiation, the photocatalytic bactericidal activity of CuL /PHI against aureus is ≈100%, achieving the same antibacterial effect as antibiotics, after 10 min of low-dose light exposure and 2 h of incubation.

Efficacy of recombinant bovine basic fibroblast growth factor to reduce hemorrhage after cervical loop electrosurgical excision procedure.

OBJECTIVE: It has been reported that recombinant bovine basic fibroblast growth factor (rbFGF) may possess possible biological functions in promoting the process of wound healing. Consequently, our study aimed to investigate the hemostatic effect of topically applied rbFGF in patients who underwent a loop electrosurgical excision procedure (LEEP). METHODS: In this retrospective analysis, we meticulously examined clinicopathologic data from a cohort of 90 patients who underwent LEEP at our institution between 2020 and 2021. Subsequently, we conducted inquiries with the patients to ascertain the degree of vaginal bleeding experienced during the postoperative periods of 3 and 6 weeks, comparing it to their preoperative menstrual flow. The magnitude of the menstrual volume alteration was then quantified using a menstrual volume multiplier(MVM). The primary endpoints of our investigation were to assess the hemostatic effect of rbFGF by means of evaluating the MVM. Additionally, the secondary endpoints encompassed the assessment of treatment-related side effects of such as infection and dysmenorrhea. RESULTS: Our findings demonstrated a significant reduction in hemorrhage following cervical LEEP. Specifically, in the per-protocol analysis, the study group exhibited a statistically significantly decrease in MVM after 3 weeks (0 [0-0] vs. 1 [0-1], respectively; p < 0.001) and after 6 weeks (1 [1] vs. 2 [1-3], respectively; p < 0.001) of the procedure. No notable disparities were observed in the remaining outcomes between the two groups. Moreover, a logistic regression analysis was employed to explore the relationship between significant bleeding and rbFGF treatment (p < 0.001, OR = -2.47, 95% CI -4.07 ~-1.21), while controlling for confounding factors such as age, BMI, and surgical specimen. CONCLUSIONS: In conclusion, our study findings highlight that the application of recombinant bovine basic fibroblast growth factorcan effectively mitigate hemorrhage subsequent to cervical loop electrosurgical excision procedure.

Co0 -Coδ+ Interface Double-Site-Mediated C-C Coupling for the Photothermal Conversion of CO2 into Light Olefins.

Solar-driven CO2 hydrogenation into multi-carbon products is a highly desirable, but challenging reaction. The bottleneck of this reaction lies in the C-C coupling of C1 intermediates. Herein, we construct the C-C coupling centre for C1 intermediates via the in situ formation of Co0 -Coδ+ interface double sites on MgAl2 O4 (Co-CoOx /MAO). Our experimental and theoretical prediction results confirmed the effective adsorption and activation of CO2 by the Co0 site to produce C1 intermediates, while the introduction of the electron-deficient state of Coδ+ can effectively reduce the energy barrier of the key CHCH* intermediates. Consequently, Co-CoOx /MAO exhibited a high C2-4 hydrocarbons production rate of 1303 µmol g-1 h-1 ; the total organic carbon selectivity of C2-4 hydrocarbons is 62.5 % under light irradiation with a high ratio (≈11) of olefin to paraffin. This study provides a new approach toward the design of photocatalysts used for CO2 conversion into C2+ products.

Atomically Dispersed Au-Assisted C-C Coupling on Red Phosphorus for CO2 Photoreduction to C2H6.

Single-atom catalysts have exhibited great potential in the photocatalytic conversion of CO2 to C2 products, but generation of gaseous multi-carbon hydrocarbon products is still challenging. Previously, supports of a single atom consist of multiple elements, making C-C coupling difficult because the coordination environment of single-atom sites is diversified and difficult to control. Here, we steer C-C coupling by implanting an Au single atom on the red phosphorus (Au1/RP), support with uniform structure composed of a single element, lower electronegativity, and better ability to absorb CO2. The electron-rich phosphorus atoms near the Au single atoms can function as active sites for CO2 activation. The Au single atom can effectively reduce the energy barrier of C-C coupling, boosting the reaction kinetics of the formation of C2H6. Notably, the C2H6 selectivity and turnover frequency of Au1/RP reach 96% and 7.39 h-1 without a sacrificial agent, respectively, which almost represents the best photocatalyst for C2 chemical synthesis to date. This research will provide new ideas for the design of high-efficiency photocatalysts for CO2 conversion to C2 products.

Engineering Water Molecules Activation Center on Multisite Electrocatalysts for Enhanced CO2 Methanation.

The renewable energy-powered electrolytic reduction of carbon dioxide (CO2) to methane (CH4) using water as a reaction medium is one of the most promising paths to store intermittent renewable energy and address global energy and sustainability problems. However, the role of water in the electrolyte is often overlooked. In particular, the slow water dissociation kinetics limits the proton-feeding rate, which severely damages the selectivity and activity of the methanation process involving multiple electrons and protons transfer. Here, we present a novel tandem catalyst comprising Ir single-atom (Ir1)-doped hybrid Cu3N/Cu2O multisite that operates efficiently in converting CO2 to CH4. Experimental and theoretical calculation results reveal that the Ir1 facilitates water dissociation into proton and feeds to the hybrid Cu3N/Cu2O sites for the *CO protonation pathway toward *CHO. The catalyst displays a high Faradaic efficiency of 75% for CH4 with a current density of 320 mA cm-2 in the flow cell. This work provides a promising strategy for the rational design of high-efficiency multisite catalytic systems.

Carbon Nitride Photocatalysts with Integrated Oxidation and Reduction Atomic Active Centers for Improved CO2 Conversion.

Single-atom active-site catalysts have attracted significant attention in the field of photocatalytic CO2 conversion. However, designing active sites for CO2 reduction and H2 O oxidation simultaneously on a photocatalyst and combining the corresponding half-reaction in a photocatalytic system is still difficult. Here, we synthesized a bimetallic single-atom active-site photocatalyst with two compatible active centers of Mn and Co on carbon nitride (Mn1 Co1 /CN). Our experimental results and density functional theory calculations showed that the active center of Mn promotes H2 O oxidation by accumulating photogenerated holes. In addition, the active center of Co promotes CO2 activation by increasing the bond length and bond angle of CO2 molecules. Benefiting from the synergistic effect of the atomic active centers, the synthesized Mn1 Co1 /CN exhibited a CO production rate of 47 µmol g-1 h-1 , which is significantly higher than that of the corresponding single-metal active-site photocatalyst.

MOF Encapsulating N-Heterocyclic Carbene-Ligated Copper Single-Atom Site Catalyst towards Efficient Methane Electrosynthesis.

The exploitation of highly efficient carbon dioxide reduction (CO2 RR) electrocatalyst for methane (CH4 ) electrosynthesis has attracted great attention for the intermittent renewable electricity storage but remains challenging. Here, N-heterocyclic carbene (NHC)-ligated copper single atom site (Cu SAS) embedded in metal-organic framework is reported (2Bn-Cu@UiO-67), which can achieve an outstanding Faradaic efficiency (FE) of 81 % for the CO2 reduction to CH4 at -1.5 V vs. RHE with a current density of 420 mA cm-2 . The CH4 FE of our catalyst remains above 70 % within a wide potential range and achieves an unprecedented turnover frequency (TOF) of 16.3 s-1 . The σ donation of NHC enriches the surface electron density of Cu SAS and promotes the preferential adsorption of CHO* intermediates. The porosity of the catalyst facilitates the diffusion of CO2 to 2Bn-Cu, significantly increasing the availability of each catalytic center.

Photocatalytic Air Purification Using Functional Polymeric Carbon Nitrides.

The techniques for the production of the environment have received attention because of the increasing air pollution, which results in a negative impact on the living environment of mankind. Over the decades, burgeoning interest in polymeric carbon nitride (PCN) based photocatalysts for heterogeneous catalysis of air pollutants has been witnessed, which is improved by harvesting visible light, layered/defective structures, functional groups, suitable/adjustable band positions, and existing Lewis basic sites. PCN-based photocatalytic air purification can reduce the negative impacts of the emission of air pollutants and convert the undesirable and harmful materials into value-added or nontoxic, or low-toxic chemicals. However, based on previous reports, the systematic summary and analysis of PCN-based photocatalysts in the catalytic elimination of air pollutants have not been reported. The research progress of functional PCN-based composite materials as photocatalysts for the removal of air pollutants is reviewed here. The working mechanisms of each enhancement modification are elucidated and discussed on structures (nanostructure, molecular structue, and composite) regarding their effects on light-absorption/utilization, reactant adsorption, intermediate/product desorption, charge kinetics, and reactive oxygen species production. Perspectives related to further challenges and directions as well as design strategies of PCN-based photocatalysts in the heterogeneous catalysis of air pollutants are also provided.

Lewis Acid Site-Promoted Single-Atomic Cu Catalyzes Electrochemical CO2 Methanation.

Developing an efficient catalyst for the electrocatalytic CO2 reduction reaction (CO2RR) is highly desired because of environmental and energy issues. Herein, we report a single-atomic-site Cu catalyst supported by a Lewis acid for electrocatalytic CO2 reduction to CH4. Theoretical calculations suggested that Lewis acid sites in metal oxides (e.g., Al2O3, Cr2O3) can regulate the electronic structure of Cu atoms by optimizing intermediate absorption to promote CO2 methanation. Based on these theoretical results, ultrathin porous Al2O3 with enriched Lewis acid sites was explored as an anchor for Cu single atoms; this modification achieved a faradaic efficiency (FE) of 62% at -1.2 V (vs RHE) with a corresponding current density of 153.0 mA cm-2 for CH4 formation. This work demonstrates an effective strategy for tailoring the electronic structure of Cu single atoms for the highly efficient reduction of CO2 into CH4.

Enhancing Visible-Light Hydrogen Evolution Performance of Crystalline Carbon Nitride by Defect Engineering.

Crystalline carbon nitride (CCN)-based semiconductors have recently attracted widespread attention in solar energy conversion. However, further modifying the photocatalytic ability of CCN always results in a trade-off between high crystallinity and good photocatalytic performance. Herein, a facile defect engineering strategy was demonstrated to modify the CCN photocatalysts. Results confirmed that the obtained D-CCN maintained the high crystallinity; additionally, the hydrogen production rate of D-CCN was approximately 8 times higher than that of CCN. Particularly, it could produce H2 even if the incident light wavelength extended to 610 nm. The significantly improved photocatalytic activity could be ascribed to the introduction of defects into the CCN polymer network to form the midgap states, which significantly broadened the visible-light absorption range and accelerated the charge separation for photoredox catalysis.

Biomimetic Donor-Acceptor Motifs in Conjugated Polymers for Promoting Exciton Splitting and Charge Separation.

Natural photosynthesis serves as a model for energy and chemical conversions, and motivates the search of artificial systems that mimic nature's energy- and electron-transfer chains. However, bioinspired systems often suffer from the partial or even large loss of the charge separation state, and show moderate activity owing to the fundamentally different features of the multiple compounds. Herein, a selenium and cyanamide-functionalized heptazine-based melon (DA-HM) is designed as a unique bioinspired donor-acceptor (D-A) light harvester. The combination of the photosystem and electron shuttle in a single species, with both n- and p-type conductivities, and extended spectral absorption, endows DA-HM with a high efficiency in the transfer and separation of photoexcited charge carriers, resulting in photochemical activity. This work presents a unique conjugated polymeric system that shows great potential for solar-to-chemical conversion by artificial photosynthesis.

Photocatalytic overall water splitting by conjugated semiconductors with crystalline poly(triazine imide) frameworks.

Photocatalytic water splitting is an ideal pathway to produce hydrogen for the future energy supply due to the sustainability of solar energy and the mild reaction conditions. In the past four decades, many inorganic semiconductor photocatalysts have been studied for this purpose. In recent years, conjugated polymers, in particular covalent carbon nitride frameworks, have rapidly emerged as a new family of photocatalysts. However, the use of conjugated photocatalysts in overall water splitting in the absence of sacrificial agents has been much less reported. Herein, we used surface kinetic control to photocatalyze overall water splitting by a covalent carbon nitride semiconductor with a crystalline poly(triazine imide) (PTI) frameworks. Our study demonstrates that the loading of a Pt co-catalyst on the PTI surface plays the key role in inducing overall water splitting. The co-deposition of a cobalt species can effectively increase the photocatalytic activity and adjust the ratio of H2 and O2 produced, as well as enhancing the stability of the photocatalyst. The optimal sample with the dual co-catalysts shows an apparent quantum yield of 2.1% for the overall water splitting reaction.

Carbon Nitride Aerogels for the Photoredox Conversion of Water.

Aerogel structures have attracted increasing research interest in energy storage and conversion owing to their unique structural features, and a variety of materials have been engineered into aerogels, including carbon-based materials, metal oxides, linear polymers and even metal chalcogenides. However, manufacture of aerogels from nitride-based materials, particularly the emerging light-weight carbon nitride (CN) semiconductors is rarely reported. Here, we develop a facile method based on self-assembly to produce self-supported CN aerogels, without using any cross-linking agents. The combination of large surface area, incorporated functional groups and three-dimensional (3D) network structure, endows the resulting freestanding aerogels with high photocatalytic activity for hydrogen evolution and H2 O2 production under visible light irradiation. This work presents a simple colloid chemistry strategy to construct 3D CN aerogel networks that shows great potential for solar-to-chemical energy conversion by artificial photosynthesis.

Tri-s-triazine-Based Crystalline Carbon Nitride Nanosheets for an Improved Hydrogen Evolution.

Tri-s-triazine-based crystalline carbon nitride nanosheets (CCNNSs) have been successfully extracted via a conventional and cost-effective sonication-centrifugation process. These CCNNSs possess a highly defined and unambiguous structure with minimal thickness, large aspect ratios, homogeneous tri-s-triazine-based units, and high crystallinity. These tri-s-triazine-based CCNNSs show significantly enhanced photocatalytic hydrogen generation activity under visible light than g-C3 N4 , poly (triazine imide)/Li+ Cl- , and bulk tri-s-triazine-based crystalline carbon nitrides. A highly apparent quantum efficiency of 8.57% at 420 nm for hydrogen production from aqueous methanol feedstock can be achieved from tri-s-triazine-based CCNNSs, exceeding most of the reported carbon nitride nanosheets. Benefiting from the inherent structure of 2D crystals, the ultrathin tri-s-triazine-based CCNNSs provide a broad range of application prospects in the fields of bioimaging, and energy storage and conversion.

A Facile Steam Reforming Strategy to Delaminate Layered Carbon Nitride Semiconductors for Photoredox Catalysis.

The delamination of layered crystals that produces single or few-layered nanosheets while enabling exotic physical and chemical properties, particularly for semiconductor functions in optoelectronic applications, remains a challenge. Here, we report a facile and green approach to prepare few-layered polymeric carbon nitride (PCN) semiconductors by a one-step carbon/nitrogen steam reforming reaction. Bulky PCN, obtained from typical precursors including urea, melamine, dicyandiamide, and thiourea, are exfoliated into few-layered nanosheets, while engineering its surface carbon vacancies. The unique sheet structures with strengthened surface properties endow PCNs with more active sites, and an increased charge separation efficiency with a prolonged charge lifetime, drastically promoting their photoredox performance. After an assay of a H2 evolution reaction, an apparent quantum yield of 11.3 % at 405 nm was recorded for the PCN nanosheets, which is much higher than those of PCN nanosheets. This delamination method is expandable to other carbon-based 2D materials for advanced applications.

The NmrA-like family domain containing 1 pseudogene Loc344887 is amplified in gallbladder cancer and promotes epithelial-mesenchymal transition.

The expression pattern and biological role of long non-coding RNA (lncRNA) in cancer has been reported to be involved in many cancers. Here, we report the expression and biological role of a newly discovered lncRNA NmrA-like family domain containing 1 pseudogene (Loc344887) in gallbladder cancer (GBC). In this study, we found that the expression of Loc344887 was significantly elevated in GBC tissues and cell lines when compared with matched normal tissues and normal epithelial bile duct cell line, respectively. High Loc344887 was associated with larger tumor size. Loc344887 was upregulated significantly after ectopic expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in GBC cells. Downregulation of Loc344887 in GBC cells suppressed cell proliferation, blocked cells in G0/S phase, and decreased the migration and invasion cell numbers. In addition, downregulation of Loc344887 decreased the expression of transcription factor Twist, mesenchymal marker Vimentin, and N-cadherin and increased the expression of epithelial maker E-cadherin, which could prompt a mesenchymal-to-epithelial transition phenotype. These results demonstrated that Loc344887 might contribute to cell proliferation and epithelial-to-mesenchymal transition process in GBC, which might be a potential therapeutic target.