Synergistic Engineering of Energy Band Alignment and Interfacial Electric Field Distribution over Bi-bismuth-Based Hetero-nanofibers for Boosting Visible-Light-Driven Photocatalytic Ammonia Synthesis and Antibiotic Removal.

Synergistic engineering of energy band alignment and interfacial electric field distribution is essential for photocatalyst design but is still challenging because of the limitation on refined regulation in the nanoscale. This study addresses the issue by employing surface modification and thermal-induced phase transformation in Bi2MoO6/BixOyIz hetero-nanofiber frameworks. The energy band alignment switches from a type-II interface to a Z-scheme contact with stronger redox potentials and inhibited electron traps, and the optimized built-in electric field distribution could be reached based on experimental and theoretical investigations. The engineered hetero-nanofibers exhibit outstanding visible-light-driven photocatalytic nitrogen reduction activity (605 µmol/g/h) and tetracycline hydrochloride removal rate (81.5% within 30 min), ranking them among the top-performing bismuth series materials. Furthermore, the photocatalysts show promise in activating advanced oxidants for efficient organic pollutant degradation. Moreover, the Bi2MoO6/Bi5O7I hetero-nanofibers possess good recycling stability owing to their three-dimensional network structure. This research offers valuable insights into heterojunction design for environmental remediation and industrial applications.

Floating metal phthalocyanine@polyacrylonitrile nanofibers for peroxymonosulfate activation: Synergistic photothermal effects and highly efficient flowing wastewater treatment.

Highly efficient floating photocatalysis has potential applications in organic pollutant treatment but remains limited by low degradation efficiency in practical applications. By introducing the photothermal effect into a peroxymonosulfate (PMS) coupled photocatalysis system, tetracycline hydrochloride (TCH) degradation could be significantly enhanced using floating metal phthalocyanine@polyacrylonitrile (MPc@PAN) nanofiber mats. MPc@PAN nanofibers with different metal centers showed similar photothermal conversion performance but different activation energies for PMS activation, resulting in metal-center-dependent synergistic photothermal effects, i.e., light-enhanced dominated, thermal-enhanced dominated, and conjointly light-thermal dominated mechanisms. The porous structures and floating ability of the FePc@PAN nanofibers provided a fast mass transfer process, with higher solar energy utilization and superior photothermal conversion performance than the FePc nanopowders. Meanwhile, the FePc@PAN nanofibers showed excellent TCH removal stability within 10 cycles (>92%) and extremely low Fe ion leaching (<0.055 mg/L) in a dual-channel flowing wastewater treatment system. This work provides new insight into PMS activation via photothermal effects for environmental remediation.

An Fc Binding Peptide-Based Facile and Versatile Build Platform for Multispecific Antibodies.

Multispecific antibodies (MsAbs) maintain the specificity of versatile antibodies while simultaneously addressing different epitopes for a cumulative, collaborative effect. They could be an alternative treatment to chimeric antigen receptor-T cell therapy by helping to redirect T cells to tumors in vivo. However, one major limitation of their development is their relatively complex production process, which involves performance of a massive screen with low yield, inconsistent quality, and nonnegligible impurities. Here, a poly(l-glutamic acid)-conjugated multiple Fc binding peptide-based synthesis nanoplatform was proposed, in which MsAbs were constructed by mixing the desired monoclonal antibodies (mAbs) with polymeric Fc binding peptides in aqueous solution without purification. To determine its efficacy, a dual immune checkpoint-based PD1/OX40 bispecific antibody and PDL1/CD3e/4-1BB trispecific antibody-based T cell engager were generated to trigger antitumor CD8+ T responses in mice, showing superior tumor suppression over free mixed mAbs. In this study, a facile, versatile build platform for MsAbs was established.

Highly dispersed g-C3N4 on well-designed three-dimensional porous nanostructured ZrO2 for high-performance photocatalytic degradation and H2 production.

A novel polymer-assisted freeze-drying method was adopted for preparing three-dimensional porous nanostructured ZrO2 (3DPZ) with macro self-supporting properties. Then, g-C3N4 was in-situ grown uniformly on the 3DPZ through a gas-solid reaction, forming 3D nanoporous ZrO2/g-C3N4 heterojunctions (3DP/ZC) with different g-C3N4 loadings that retained self-supporting characteristics. The kapp value of Rhodamine B (RhB) degradation and H2 evolution rate of the 3DP/ZC-2 under visible light reached 0.035 min-1 and 1013.1 µmol h-1 g-1, which were 19.6 and 6.6 times higher than pure g-C3N4, respectively. The ZrO2 nanoparticles (ZNps) prepared via freeze-drying, but without polymer precursor, were used as support to form ZrO2/g-C3N4 nanoparticles (ZCNps-2) for comparison study. The RhB degradation rate and H2 evolution rate of the 3DP/ZC-2 under visible light were about 3.7 and 5.3 times higher than ZCNps-2. Their enhanced photocatalytic activity could be attributed to their unique 3D heterointerface with matched energy bands for rapid charge separation and transfer and a hierarchical porous structure for mass transfer and surface reaction processes. The scavenger trapping and ESR measurements confirmed that the primary reactive radicals for degradation were superoxide radical ions (⋅O2-), hydroxyl radicals (⋅OH), and photogenerated holes (h+). The pH-dependent photocatalytic degradation activity originated from the H+-related ⋅OH conversion reaction. Besides, the macro self-supporting nature could provide excellent separability and recyclability, and self-supporting membranes were also constructed and demonstrated as stable and recyclable photocatalysts. This work provides a new routine for designing 3D-heterojunctions as new kinds of functional materials for applications in environmental remediation and green energy production.

Oxidation of phthalate acid esters using hydrogen peroxide and polyoxometalate/graphene hybrids.

Phthalate acid esters (PAEs) have been adsorbed and oxidatively degraded into small molecules including lactic acid (LA), formic acid (FA), H2O and CO2 using polyoxometalates (POMs)/graphene hybrids. We demonstrated that super-lower concentrations of PAEs could be oxidized, which was due to their unique structure. POM molecules have been embedded onto graphene to form H5PMo10V2O40@surfactant(n)/Graphene(L wt%) (abbreviated as HPMoV@Surf(n)/GO(L wt%)) using surfactants with the carbon chain length n = 2, 4, 6 and 8 for the loading of HPMoV. The coexistence of the graphene and surfactant layer (on HPMoV@Surf(n)/GO(20 wt%)) adsorbed PAE molecules and transported them rapidly to HPMoV active sites. And n values determined the electron transfer ability between graphene and POMs that promoted PAEs oxidation. The loading of POMs on the surface of graphene permitted HPMoV@Surf(n)/GO(L wt%) act as interfacial catalyst which degraded various PAEs (i.e., diethyl phthalate (DEP), diallyl phthalate (DAP) and di (2-ethylhexyl) phthalate (DEHP)) while removed more than 70% of TOC and COD. The degradation of DEP achieved 93.0% with HPMoV@Surf(n)/GO(20 wt%) and H2O2, which followed first-order kinetics and the reaction activation energy (Ea) of 23.1 kJ/mol. Further, HPMoV@Surf(n)/GO(20 wt%) showed potential for the removal of PAEs in Wastewater Treatment Plant (WWTP), and the degradation efficiency for PAE (DEP) in secondary effluent achieved 55.0%. In addition, the loading method for POMs on graphene eliminated the leaching of POMs from graphene, and the degradation efficiency could still reach 88.1% after ten recycles.

Anchoring bismuth oxybromo-iodide solid solutions on flexible electrospun polyacrylonitrile nanofiber mats for floating photocatalysis.

Constructing floating photocatalysts with highly efficient visible-light utilization is a promising approach for practical photocatalytic wastewater treatment. In this study, we anchored bismuth oxybromo-iodide (BiOBrxI1-x (0 ≤ x ≤ 1)) on flexible electrospun polyacrylonitrile (PAN) nanofiber mats to create BiOBrxI1-x@PAN nanofibers with tunable light absorption properties as floating photocatalysts at room temperature. As x increased, the photocatalytic activity of the BiOBrxI1-x@PAN nanofibers with similar loading content initially increased, and then decreased, for the degradation of bisphenol A (BPA) and methyl orange (MO) under visible-light irradiation (λ > 420 nm) conditions. The BiOBrxI1-x@PAN (0 < x < 1) nanofibers exhibited better photocatalytic performance compared to the BiOBr@PAN and BiOI@PAN nanofibers. Under visible-light irradiation, the BPA degradation rate of the BiOBr0.5I0.5@PAN nanofibers was 1.9 times higher than that of the BiOI@PAN nanofibers, while the BiOBr@PAN nanofibers had no noticeable degradation performance. The MO degradation rate of the BiOBr0.5I0.5@PAN nanofibers was 2.5 and 3.2 times higher than that of the BiOBr@PAN and BiOI@PAN nanofibers, respectively. The enhanced performance possibly originated from a balance between the light absorption and redox capabilities, along with efficient separation of electron-hole pairs in the BiOBr0.5I0.5@PAN nanofibers, as determined by ultraviolet-visible diffuse reflectance spectroscopy, X-ray photoelectron spectra analysis of the valence bands, and photocurrent response characterization. Compared to the powder structures, the BiOBrxI1-x@PAN nanofibers showed enhanced performance due to the excellent dispersion and immobilization of the BiOBrxI1-x solid solution, which provided more active sites during photocatalytic degradation. In addition, their flexible self-supporting structures allowed for floating photocatalysis near the water surface. They could be reused directly without separation and maximized the absorption of visible light during the photocatalytic reaction. Therefore, these solid-solution-based floatable nanofiber photocatalysts are good potential candidates for wastewater treatment applications.

Flexible All-Inorganic Room-Temperature Chemiresistors Based on Fibrous Ceramic Substrate and Visible-Light-Powered Semiconductor Sensing Layer.

As the most extensively used gas-sensing devices, inorganic semiconductor chemiresistors are facing great challenges in realizing mechanical flexibility and room-temperature gas detection for developing next-generation wearable sensing devices. Herein, for the first time, flexible all-inorganic yttria-stabilized zirconia (YSZ)/In2 O3 /graphitic carbon nitride (g-C3 N4 ) (ZIC) gas sensor is designed by employing YSZ nanofibers as substrate, and ultrathin In2 O3 /g-C3 N4 heterostructures as active sensing layer. The YSZ substrate possesses small nanofiber diameter (310 nm), ultrafine grain size (23.9 nm), and abundant dangling bonds, endowing it with striking mechanical flexibility and strong adhesion with In2 O3 /g-C3 N4 sensing layer. Meanwhile, the ultrathin thickness (≈7 nm) of In2 O3 /g-C3 N4 ensures that the inorganic sensing layer has tiny linear strain along with the deformation of flexible YSZ substrate, thereby enabling unusual bending capacity. To address the operating temperature issue, the gas sensor is operated by using a visible-light-powered strategy. Under visible-light illumination, the flexible ZIC sensor exhibits a perfectly reversible response/recovery dynamic process and ultralow detection limit of 50 ppb to toxic nitrogen dioxide at room temperature. This work not only provides an insight into the mechanical flexibility of inorganic materials, but also offers a valuable reference for developing other flexible inorganic-semiconductor-based room-temperature gas sensors.

A self-floating electrospun nanofiber mat for continuously high-efficiency solar desalination.

Solar desalination is an environment-friendly and sustainable technology to address the shortage of freshwater resources. However, it still faces huge challenges to develop a salt-rejection solar desalination system with continuous high efficiency. Herein, an electrospun nanofiber mat was fabricated for continuously high-efficiency solar desalination with carbon nanotube as a photothermal material, polyvinylidene fluoride as a floating support material and polyvinylpyrrolidone as a pore-forming agent. The porous structure and superhydrophilic surface provide significant water transport channels and thus avoid salt deposition, even in the high-salinity brine (20 wt% NaCl). The integration of strong broadband absorption property, excellent photothermal performance, floatability, durability and stability endows the solar desalination system with continuously high evaporation efficiency. The evaporation rate and solar conversion efficiency reached up to 1.372 kg m-2 h-1 and 86.1%, respectively, in simulated seawater under one sun irradiation and lasted for 11 h with little fluctuation. This work opens a new avenue for the rational design and fabrication of solar desalination systems to promote practical application.

Construction of In2O3/ZnO yolk-shell nanofibers for room-temperature NO2 detection under UV illumination.

Room-temperature gas sensors have emerged as effective platforms for sensing explosive or toxic gases in ambient environment. However, room-temperature gas sensor usually suffers from extremely poor sensitivity and sluggish response/recovery characteristics due to the low reacting activity at low temperature. Herein, we present a room-temperature NO2 sensor with greatly enhanced sensitivity and rapid response/recovery speed under ultraviolet (UV) illumination. The sensor based on In2O3/ZnO yolk-shell nanofibers exhibits remarkable sensitivity (Rg/Ra = 6.0) to 1 ppm NO2 and rapid response/recovery time (≤36, 68 s) under UV illumination, obviously better than negligible sensing performance and inefficient response/recovery properties in dark condition. Such excellent gas sensing properties of the In2O3/ZnO yolk-shell nanofibers were not only attributed to the improved photo-generated charge separation efficiency derived from the effect of heterojunction, but also related to the enhanced receptor function towards NO2 endowed by increased reactive sites and gas adsorption. These proposed strategies will provide a reference for developing high-performance room-temperature gas sensors.

Discrete heterojunction nanofibers of BiFeO3/Bi2WO6: Novel architecture for effective charge separation and enhanced photocatalytic performance.

Designing and constructing one-dimensional (1D) discrete heterojunctions comprise an ideal strategy to improve the charge-separation efficiency and enhance the photocatalytic activities of semiconductor materials. Here, a novel architecture of discrete heterojunction nanofibers (DH-NFs) was obtained by growing Bi2WO6 nanosheets (NSs) on electrospun BiFeO3 nanofibers (NFs) via solvothermal technology. The charge-separation efficiency of BiFeO3/Bi2WO6 DH-NFs was approximately 2 times higher than that of BiFeO3 NFs and Bi2WO6 NSs. As expected, the BiFeO3/Bi2WO6 DH-NFs exhibited enhanced photocatalytic activities for oxygen evolution and RhB degradation. The reaction rates of BiFeO3/Bi2WO6 DH-NFs for oxygen evolution and RhB degradation were 18.3 and 36.7 times higher, respectively, than those of BiFeO3 NFs, and 31.9 and 8.7 times higher than those of Bi2WO6 NSs, respectively. The improved charge-separation efficiency and enhanced photocatalytic activities of BiFeO3/Bi2WO6 DH-NFs could be attributed to the following three points. The 1D heterojunctions could realize the separation and axial transport of photogenerated charges. The discrete structure could facilitate the spatial separation of redox reaction sites as well as photogenerated charges. The high surface area of BiFeO3/Bi2WO6 DH-NFs might provide more active sites for photocatalytic reaction. Moreover, the BiFeO3/Bi2WO6 DH-NFs possessed good recycling performance owing to the magnetic-separable property derived from the ferromagnetic behavior of BiFeO3.

TiO2/SrTiO3/g-C3N4 ternary heterojunction nanofibers: gradient energy band, cascade charge transfer, enhanced photocatalytic hydrogen evolution, and nitrogen fixation.

TiO2/SrTiO3/g-C3N4 ternary heterojunction nanofibers with a cascade energy band alignment were designed and then fabricated by a combination of electrospinning technology and gas-solid reaction. Their photocurrent responses were 1.4 and 1.8 times higher while their transient photoluminescence lifetime were about 0.75 and 0.79 times shorter than those of TiO2/g-C3N4 nanofibers and SrTiO3/g-C3N4 nanofibers, respectively. The enhanced photocurrent response, decreased lifetime, and their dramatically decreased photoluminescence intensity clearly indicated that highly efficient cascade charge transfer and separation were achieved in the ternary nanofibers with the gradient energy band alignment compared with the corresponding traditional binary nanofibers noted above. When tested in photocatalytic reduction reactions of H2 evolution and nitrogen fixation, the corresponding reaction rates under simulated sunlight irradiation values of 1304 µmol g-1 h-1 and 2192 µmol g-1 h-1 L-1 were 2.1 and 1.9 times better than those of TiO2/g-C3N4 nanofibers and 4.2 and 3.3 times better than those of SrTiO3/g-C3N4 nanofibers, respectively. Furthermore, the photocatalytic activities of the TiO2/SrTiO3/g-C3N4 nanofibers had no significant decrease after several cycles, indicating that they possessed good structural stability properties. This work provides a new route to design and fabricate an efficient photocatalyst for photocatalytic reduction reactions.

Direct Z-scheme heterostructure of p-CuAl2O4/n-Bi2WO6 composite nanofibers for efficient overall water splitting and photodegradation.

Constructing heterostructures can facilitate photoinduced charge separation, leading to enhanced photocatalytic performance. However, spatial separation of charge carriers in traditional type II heterojunctions is at the expense of their redox ability. In this paper, well-designed direct Z-scheme systems (ZSS) of p-CuAl2O4/n-Bi2WO6 composite nanofibers with uniform non-woven web nanostructure was built by electrospinning technique and solvothermal reactions. The formation mechanism of the ZSS and the charge migration pathway is investigated in detail. Results show that as-prepared composite nanofibers exhibit desirable photocatalytic performance for overall water splitting due to its stronger redox power and efficient charge separation. Meantime, it shows great activity for photodegradation of various organic pollutant models (RhB, MO, 4-NP), which is 1 order of magnitude higher than the single-component CuAl2O4 and Bi2WO6. Furthermore, the composite nanofibers exhibit well separable properties by natural sedimentation because of its ultra-long and non-woven web nanostructure. The paper explores CuAl2O4 and its Z-scheme heterostructures in water splitting for the first time, which may highlight its new applications.

Immobilization of ultrafine Ag nanoparticles on well-designed hierarchically porous silica for high-performance catalysis.

Catalyst immobilization is of much significance not only for maintaining the high activity of the ultrafine catalyst, but also for the separation of catalyst during the practical application. Herein, a novel support material, three-dimensional hierarchically porous silica (HPS) with interconnected micro-meso-macro pores and high specific surface area was successfully fabricated though a freeze-drying technique in the presence of poly(vinyl alcohol) (PVA) and subsequent calcination process. A series of characterizations revealed that the specific surface area of HPS can be well adjusted by changing the addition of PVA. The specific surface area of HPS was as high as 360 m2 g-1, which was 211-fold higher than HPS-0 (silica prepared without using PVA). To demonstrate the potential application of such novel support material, highly dispersed silver nanoparticles (AgNPs) were immobilized on the surfaces of HPS and HPS-0 through in-situ reduction. By contrast, the catalytic activity of AgNPs anchored on HPS (531 s-1 g-1) was about 42-fold higher than that of AgNPs anchored on HPS-0 (12.67 s-1 g-1). The significantly enhanced catalytic activity of AgNPs/HPS was believed to be related to their high specific surface area and interconnected macroporous scaffolds, which could provide numerous reactive sites and mass transfer routes for the reactants.

Bi2MoO6/BiFeO3 heterojunction nanofibers: Enhanced photocatalytic activity, charge separation mechanism and magnetic separability.

Uniform Bi2MoO6 nanosheets were grown in a high dispersed fashion on electrospun BiFeO3 nanofibers via a solvothermal technique. The loading amount of Bi2MoO6 in the Bi2MoO6/BiFeO3 heterojunction nanofibers could be controlled by adjusting the precursor concentrations in the solvothermal process. The XPS analysis, energy band position calculation and trapping experiments all proved that the Bi2MoO6/BiFeO3 heterojunction is a Z-scheme heterojunction. The Z-scheme Bi2MoO6/BiFeO3 heterojunction had a much higher photocatalytic activity in the visible-light photodegradation of Rhodamine B (RhB) and tetracycline hydrochloride (TC) than pure BiFeO3 nanofibers or pure Bi2MoO6 nanosheets. The enhanced photocatalytic activity was attributed to the formation of Z-scheme Bi2MoO6/BiFeO3 heterojunctions, which could be beneficial to the separation of photogenerated electron-hole pairs. Moreover, the Bi2MoO6/BiFeO3 heterojunction nanofibers could be easily separated under an external magnetic field via the ferromagnetic BiFeO3. After several cycles, the photocatalytic activity of the Bi2MoO6/BiFeO3 heterojunction no longer significantly decreased suggesting that the Bi2MoO6/BiFeO3 heterojunction is stable. These Z-scheme Bi2MoO6/BiFeO3 heterojunction nanofibers with highly visible-light photocatalytic activity, excellent chemical stability and magnetic separability could be useful in many practical applications.

Bismuth oxychloride (BiOCl)/copper phthalocyanine (CuTNPc) heterostructures immobilized on electrospun polyacrylonitrile nanofibers with enhanced activity for floating photocatalysis.

The 2,9,16,23-tetranitro phthalocyanine copper (II) nanostructures and bismuth oxychloride nanosheets were grown on electrospun polyacrylonitrile (PAN) nanofibers in sequence by solvothermal method. As a result, the BiOCl/CuTNPc heterostructures were uniformly immobilized on the PAN nanofibers. The obtained BiOCl/CuTNPc/PAN nanofibers had excellent photocatalytic activity for the degradation of rhodamine B (RhB) under UV-vis light irradiation. The first-order rate constant of the BiOCl/CuTNPc/PAN nanofibers was 5.86 and 6.31 times as much as CuTNPc/PAN and BiOCl/PAN nanofibers, respectively. The high photocatalytic activity could be attributed to the formation of BiOCl/CuTNPc heterostructures, which helped the separation of the photogenerated electron-hole pairs. Concurrently, the marcoporous structure of the BiOCl/CuTNPc/PAN nanofibers improved the photocatalytic activity due to the increased interface contacts between the photocatalyst and the RhB solution. The BiOCl/CuTNPc/PAN nanofibers did not need to be separated for reuse due to their flexible self-supporting properties originating from the PAN nanofibers. Moreover, the film-like BiOCl/CuTNPc/PAN nanofibers could float easily on the liquid and maximize the absorption of sunlight during photocatalysis. It was expected that the BiOCl/CuTNPc/PAN nanofibers with high photocatalytic activity and easily separable property will possess great potential in the field of industrial applications and environmental remediation.

Molybdenum diselenide nanosheet/carbon nanofiber heterojunctions: Controllable fabrication and enhanced photocatalytic properties with a broad-spectrum response from visible to infrared light.

Molybdenum diselenide nanosheet/carbon nanofiber (MoSe2/CNF) heterojunctions have been successfully obtained by a facile two-step synthesis route combining an electrospinning technique and solvothermal method. The results show that MoSe2 nanosheets distributed evenly on the carbon nanofibers without aggregation, and the loading amount of MoSe2 could be well controlled by adjusting the reactant concentrations during the solvothermal process for the fabrication of the MoSe2/CNF heterojunctions. The as-prepared MoSe2/CNF heterojunctions exhibited higher photocatalytic activity than pure MoSe2 for the degradation of Rhodamine B (RhB) under visible and infrared light irradiation. The normalized rate constant for the MoSe2/CNF heterojunctions was nearly 3.2 times and 1.6 times higher than that of pure MoSe2 under visible light and infrared light (1.5 W, 980 nm laser) irradiation, respectively. The enhanced photocatalytic activity might be attributed to the formation of heterojunctions, which could improve the separation of photogenerated electrons and holes at the MoSe2/CNF heterojunctions interface. In addition, MoSe2/CNF heterojunctions could be efficiently separated from the solution by sedimentation due to their ultralong one-dimensional and self-supporting structure. Such MoSe2/CNF heterojunctions with a broad-spectrum-response photocatalytic performance might have potential applications in water treatment.

Hierarchical heterostructures of p-type bismuth oxychloride nanosheets on n-type zinc ferrite electrospun nanofibers with enhanced visible-light photocatalytic activities and magnetic separation properties.

P-type bismuth oxychloride (p-BiOCl) nanosheets were uniformly grown on n-type zinc ferrite (n-ZnFe2O4) electrospun nanofibers via a solvothermal technique to form hierarchical heterostructures of p-BiOCl/n-ZnFe2O4 (p-BiOCl/n-ZnFe2O4 H-Hs). The density and loading amounts of the BiOCl nanosheets with exposed {0 0 1} facets were easily controlled by adjusting the reactant concentration in the solvothermal process. The p-BiOCl/n-ZnFe2O4 H-Hs exhibited enhanced visible-light photocatalytic activities for the degradation of Rhodamine B (RhB). The apparent first-order rate of the p-BiOCl/n-ZnFe2O4 H-Hs and its normalized constant were about 12.6- and 8-fold higher than pure ZnFe2O4 nanofibers. This suggests that both the improved charge separation efficiency from the uniform p-n heterojunctions and the enlarged active surface sites from the hierarchical structures increase the photocatalytic performances. Furthermore, the p-BiOCl/n-ZnFe2O4 H-Hs could be efficiently separated from the solution with an external magnetic field via the ferromagnetic behavior of ZnFe2O4 nanofibers. The magnetic p-BiOCl/n-ZnFe2O4 H-Hs with enhanced visible-light photocatalytic performances might have potential applications in water treatment.

Three dimensional hierarchical heterostructures of g-C3N4 nanosheets/TiO2 nanofibers: Controllable growth via gas-solid reaction and enhanced photocatalytic activity under visible light.

Graphitic C3N4 nanosheets were uniformly grown on electrospun TiO2 nanofibers with three-dimensional nanofibrous networks via a facial gas-solid reaction. The mass loading of g-C3N4 nanosheets could be easily controlled by adjusting the mass ratios of gaseous precursors (urea) to TiO2 NFs. The three-dimensional hierarchical heterostructures of g-C3N4 nanosheets/TiO2 nanofibers could be obtained with excellent distribution and high specific surface area of 121.5m2g-1, when the mass loading of g-C3N4 was 59.8wt.%. Under visible light irradiation, the degradation rate constant (rhodamine B) and the H2 evolution rate of the heterostructures were about 4.6 and 1.6 times of pure g-C3N4, while 23 and 167.8 times of TiO2 nanofibers, respectively. Their enhanced performance could be attributed to the effective charge separation and electron transfer process. Our work provides an attractive strategy to construct various three-dimensional hierarchical heterostructures of g-C3N4 nanosheets for environmental and energy applications.

Octahedral-Like CuO/In2O3 Mesocages with Double-Shell Architectures: Rational Preparation and Application in Hydrogen Sulfide Detection.

This contribution describes a facile strategy for constructing octahedral-like CuO/In2O3 mesocages with double-shell architectures. The synthetic method included first preparation of unifrom Cu2O as an ideal self-sacrificial template and then decoration by a In2O3 outer layer through room-temperature Cu2O-engaged redox etching reaction combined with subsequent annealing process. Various characterization techniques manifested that In2O3 nanoparticles were uniformly grown on the surface of CuO mesocages, resulting in a well-defined double-shelled heterostructure. When evaluated as a novel sensing material for hydrogen sulfide (H2S) detection, the resultant octahedral-like CuO/In2O3 heterostructures exhibited obviously enhanced sensing response, lower operating temperature as well as faster response/recover speed during the dynamic measurement compared to the pristine CuO particles, which is likely related to the high-level of adsorbed oxygen concentration, resistance modulation effect, and unique microstructure of as-prepared CuO/In2O3 heterostructure.

Facile in situ synthesis of plasmonic nanoparticles-decorated g-C3N4/TiO2 heterojunction nanofibers and comparison study of their photosynergistic effects for efficient photocatalytic H2 evolution.

Ternary heterostructured nanofibers (NFs) consisting of plasmonic noble metal nanoparticles (Au, Ag, or Pt NPs), graphitic carbon nitride nanosheets (g-C3N4 NSs), and TiO2 NPs were synthesized in situ via a facile electrospinning technique combined with a subsequent thermal oxidation/reduction process. The thermal-reduced plasmonic NPs with sizes from 5 to 10 nm are dispersed uniformly into the heterojunctions of the NFs that are formed by thermal oxidation etching of exfoliated g-C3N4 NSs in the electrospun TiO2 nanofibrous matrix, as evidenced by microscopic and electronic structure analyses. In comparison to single-component photocatalysts, such as g-C3N4 NSs or TiO2 NFs, these ternary heterostructures exhibit significantly high photocatalytic activity for H2 evolution under simulated sunlight irradiation. The enhanced photoactivities are attributed to the strong photosynergistic effect between the surface plasmon resonance (SPR) and the heterojunction interface sensitization, which results in the improvement of charge-carrier generation and separation in the ternary heterostructured NFs. Further investigations indicate that coupling heterojunction sensitization on the g-C3N4/TiO2 interface with Ag SPR effects by plasmonic resonant energy transfer is the optimal strategy for synergistically improving the charge-carrier kinetics to achieve highly efficient photocatalytic H2 evolution. It is believed that our present study offers a promising method for the rational integration of multi-component photocatalytic systems that can realize high photocatalytic performances for use in solar-to-fuel conversion.