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Wearing face masks is the best way to stop the spread of respiratory infections. However, if masks are not sterilized, changing them too frequently can actually increase the risk of cross‐contamination. Herein, the construction of an antipathogen photocatalytic mask with carbon vacancy‐modified carbon nitride nanosheets (g‐C3N4‐VC Ns) coated on the non‐woven fabrics of the out layer of the mask, offering effective and long‐term protection against damaging pathogens when exposed to light is reported. The introduced carbon vacancies are found capable of creating energy‐disordered sites and inducing energetic electric force to overcome the Coulomb interactions between electron‐hole pairs, thus promoting the electron‐hole separation to achieve a high generation of reactive oxygen species (ROS). Thanks to its high activity in generating ROS upon exposure to light, the as‐prepared photocatalytic mask shows high pathogen sterilization performance. This, in turn, prolongs the mask's protective lifetime, decreases the need for regular replacement, and decreases medical waste production. The work demonstrated here opens new viewpoints in designing pathogens biocidal protective devices for health protection, offering significant promise in specific environment self‐protection. [ABSTRACT FROM AUTHOR]

A series of Bi2Sn2O7 photocatalysts was developed with the aim to regulate defect chemistry as well as electronic structure by modulating the charge states of tin species for boosting photocatalytic selective oxidation of alcohols performance. Defective centers, such as oxygen vacancies (OVs), were beneficial to enhancing the adsorption and activation of molecular oxygen. Meanwhile, the valence band edge potential of Bi2Sn2O7 with higher OVs content exhibited a distinct downshift, improving the thermodynamical driving force of photooxidation. Additionally, OVs contributed to promoting the separation efficiency of photogenerated carriers, which can be confirmed by the surface photovoltage measurement. By optimizing the electronic structure as well as defect chemistry, the optimal benzyl alcohol conversion efficiency was 76.0 % with selectivity toward benzaldehyde being about 100 %. It's found that photogenerated holes and.O2− active species played critical role in photocatalytic aerobic oxidation. This work may provide a novel insight to clarify the role of defect chemistry during the selective benzyl alcohol oxidation over Bi2Sn2O7 photocatalyst. [ABSTRACT FROM AUTHOR]

A series of Ag3PO4/Bi2MoO6 p-n heterojunctions were assembled via the thin Bi2MoO6 nanosheets attached to the surface of rhombic dodecahedral Ag3PO4. The self-optimized Ag+/Ag0 pairs existed in the as-prepared heterojunction which are regarded as charge transmission bridge to accelerate the reaction. The samples presented much higher photocatalytic activity for the degradation of the target pollutions (completely degradation under solar light illuminating of 70 min for rhodamine B, 80 min for aureomycin and 70 min for tetracycline). It was found during the recycle test, photocatalytic performance of Ag3PO4/Bi2MoO6 underwent a successive increase since the second cycle in which the completely degradation of RhB was achieved after only 60 min visible light irradiation, confirming the composite is reusable with well stability. The oxidative mechanism was carefully investigation based on the scavengers trapping test, ESR spectra, XPS spectrum, photocurrent responses, and electrochemical impedance spectroscopy analysis. It proved Ag0 gradually generated from the as-prepared composite under solar light illuminating is fixed at an optimized content. The charge transfer was consequentially enhanced during the suitable level turning of Ag+/Ag0 pairs. Mediated by Ag0 sandwiched in p-n junction, the active species of the present photooxidative reaction experienced various period from ·OH and h+ in the initial reaction to the additional ·O2− in the successive recycle experiment owing to generation of the rectifying contact and Schottky junction. This study provides a new cognition for the improved reusability of the photocorrosion materials via the mutual transformation of metal monomers and ions. [ABSTRACT FROM AUTHOR]

In this work, we report the synthesis of Na2Ta2O6/Ag heterojunctions with the aim of tailoring their structural, electronic and photocatalytic properties. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, UV-vis optical diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The effects of silver doping and heterojunctions on the electronic structure and photodegradation of a rhodamine B dye solution were investigated experimentally and theoretically. It was found that silver played critical roles in modulating the electronic structure, defect chemistry and visible light photocatalytic activity. Partial incorporation of Ag ions into the Na2Ta2O6 host lattice led to a monotonous lattice expansion and introduced an interband for band gap narrowing. Meanwhile, some of the Ag ions were reduced, and crystallized into Ag nanoparticles on Na2Ta2O6 surfaces that can promote the visible light absorption efficiency of Na2Ta2O6/Ag heterojunctions. Moreover, the doping and heterojunction of silver can also result in the modulation of defective oxygen species that have a great impact on photocatalytic performance. As a consequence of the well-controlled electronic structure, surface defect chemistry, Ag particle size, BET surface area, and Ag+ doping effects, the photocatalytic performance of the Na2Ta2O6/Ag heterojunctions was optimized at an as-measured Ag/Ta molar ratio of 1.17. [ABSTRACT FROM AUTHOR]

The present work reports the preparation of a short-ordered Na xTaO y ⋅ n H2O catalyst that exhibits exceptional and highly efficient photocatalytic reactivity toward aerobic oxidation relative to its crystalline counterpart. Synchrotron radiation wide-angle X-ray scattering and transmission electron microscopy results indicated that the as-synthesized catalyst shows short-ordered features with well-controlled short-range ordering limits and defect chemistry. The short-ordered structure of Na xTaO y ⋅ n H2O predicted large amounts of defective centers and high surface areas that may play critical roles in visible-light harvesting and photocatalytic aerobic oxidation. This work may provide a novel strategy for the development of short-ordered catalytic systems with well-controlled defect chemistry that exhibit highly efficient photocatalytic properties. [ABSTRACT FROM AUTHOR]

Pure and vanadium doped NaTaO3 nanoparticles were synthesized by hydrothermal conditions. From XRD studies, both pure as well as vanadium doped NaTaO3 are found to show pure orthorhombic phase of tatanlate. STEM studies show the formation of cube shape particles in all the samples with a particle size about 70 nm. UV-vis diffuse reflectance spectra clearly indicates the red-shift in the series of vanadium doped NaTaO3 catalysts, resulting in a decrease in the band gap of NaTaO3 caused by substitution of V5+ ions at Ta5+ site with an increase of vanadium doping concentration in NaTaO3. The results reveal that Vanadium doped NaTaO3 show good photocatalytic performance under visible light and RhodamineB (RB) degradation is improved with Vanadium doping. The photocatalytic mechanism was discussed by density functional theory. V5+ ions substitution of Ta5+ ions results in an intermediate band (IB) below the bottom of the conduction band (CB), which is mainly attributed to the state of V 3d. Meanwhile the broadening of valence band is formed due to the hybridization between the V 3d and O 2p states. Both these factors increase the transient behavior of the photogenerated charge carriers and inhibit the recombination of e–h+ pairs, showing enhanced activities over the entire visible region. [ABSTRACT FROM AUTHOR]

Abstract: Composite photocatalysts TiO2 immobilized on granular activated carbons with different porosities (TiO2/AC) were prepared by a novel approach, dip-hydrothermal method using peroxotitanate as precursor. The TiO2/AC composites were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and the nitrogen absorption. Their photocatalytic activity was evaluated by degradation of methyl orange (MO). The results showed that nano-TiO2 particles of anatase type were well deposited on the activated carbon surface. The porosity of activated carbon had significant influence on the adsorption, the amount of TiO2 deposited on the external surface of AC and the activity of composite photocatalysts. The composite TiO2/AC made from proper mesoporosity AC exhibited higher catalytic activity than the mixture of powdered TiO2 with AC. Furthermore, the mechanism of synergistic effect of AC adsorption and TiO2 photocatalysis was discussed. [Copyright &y& Elsevier]

Abstract: TiO2 photocatalysts deposited on activated carbon (TiO2/AC) were prepared by dip-hydrothermal method at 180°C using peroxotitanate as a precursor, then calcinated at 300–800°C. The samples were characterized by X-ray diffraction, scanning electron microscopy, Raman spectroscopy and the nitrogen absorption. Their photocatalytic activity was evaluated by degradation of methyl orange (MO). The results showed that TiO2 particles of anatase type were well deposited on the activated carbon surface. TiO2/AC calcinated at 600°C exhibited the best photocatalytic performance. For the comparison, the same photocatalysis experiment was carried out for two mixtures of commercial TiO2 (Degussa P25) with AC and synthetic TiO2 with AC. It was found that the composite catalyst TiO2/AC was better than the two mixtures. Besides, different from fine powdered TiO2, the granular TiO2/AC photocatalysts could be easily separated from the bulk solution and reused; indeed, its photocatalytic ability was hardly decreased after a five-cycle for MO degradation. The kinetics of the MO degradation fitted well the Langmuir–Hinshelwood model. [Copyright &y& Elsevier]

Abstract: The clarification of the excited states dynamics on TiO2 surface is important subject for the design of the highly active photocatalysts. In the present study, we applied our novel tight-binding quantum chemical molecular dynamics method to the investigation on the photocatalytic oxidation dynamics of acetone by photogenerated radicals on the hydrated anatase TiO2 surface. The elucidated photocatalytic reaction mechanism strongly supports the previous experimental proposal and finally the effectiveness of our new approach for the clarification of the photocatalytic reaction dynamics employing the large simulation model was confirmed. [Copyright &y& Elsevier]

The dielectric barrier discharge plasma (DBDP) process has received extensive attention for the removal of organic contaminants from water. A novel microwave-assisted hydrothermal method was used to easily and rapidly synthesize MnFe 2 O 4 catalysts. Based on the DBDP process, MnFe 2 O 4 can enhance 4-fluorophenol (4-FP) abatement from 44.15% to 58.78% through the catalysis within 18 min. Then, the adjunction of O 3 generated by discharge can further boost 4-FP degradation to 94.94%. After the whole optimization process is complete, the associated pseudo-first-order reaction kinetic constant and energy efficiency were enhanced from 0.0327 to 0.1536 min−1 and 2067.13 mg kW h−1 to 4444.75 mg kW h−1, respectively. With the help of the condition, blank and radical capture experiments, the catalytic performance caused by MnFe 2 O 4 and O 3 was attributed to the joint action of Fenton-like reactions, photocatalysis (ultraviolet, UV), photoassisted Fenton reactions and O 3 catalysis. The overall downward trend of the possible intermediate toxicities indicated that the DBDP/MnFe 2 O 4 /O 3 process can effectively remove and mineralize 4-FP without the generation of more toxic intermediates. In addition, during the 5 cycles, MnFe 2 O 4 can maintain excellent recovery, efficiency and durability. In summary, the coupling of discharge plasma and MnFe 2 O 4 sheds new light on catalysis for wastewater treatment. [Display omitted] • MnFe 2 O 4 was obtained through microwave-assisted synthesis. • Excellent catalytic performance was formed between MnFe 2 O 4 and DBDP. • Catalysis essence was the promotion of •OH generation through multiple AOPs. • MnFe 2 O 4 was easily recovered from solution. [ABSTRACT FROM AUTHOR]

A series of CsTaWO6/g-C3N4 composite photocatalysts were successfully prepared aiming to regulate the charge kinetics for spatial separating the photoinduced electrons and holes under visible light irradiation, which was ascribed to the matched band edge alignment of CsTaWO6 and g-C3N4. Careful characterization on the as-prepared photocatalysts indicated the co-existent of g-C3N4 and CsTaWO6 in the composite. Because of electronic structure match and fine interfacial contact, CsTaWO6 anchored with g-C3N4 can enhance the visible light harvesting capacity and the photocatalytic activity toward hydrogen evolution was greatly improved with an optimized evolution rate of 7.5 μmol·g−1·h−1 and an excellent photocatalytic stability was achieved. The enhancement of photocatalytic activity was attributed to the fact that photoinduced electrons in the conduction band of g-C3N4 can be efficiently injected into the conduction band of CsTaWO6, leading to spatial charge separation between g-C3N4 and CsTaWO6, which can be confirmed by incident photocurrent responses and electrochemical impedance curves.The charge kinetics for the spatial isolation of photogenerated charge carrier and the visible light harvesting capacity were enhanced by constructing CsTaWO6/g-C3N4 composite photocatalysts, leading the photocatalytic activity toward hydrogen evolution improved. [ABSTRACT FROM AUTHOR]

• A photo-recyclable feather biochar (PFB) was prepared via a self-crosslinking method. • The multilayered graphene like structure of PFB was decorated with TiO 2 nanoparticle. • PFB presented synergistic property of both adsorption and visible light degradation. • The mineralization ability of PFB was well evaluated via mass spectrum experiments. Inspired by its special micro-architecture of β-folding layers, the wasted poultry feather was utilized to synthesize a photo-recyclable feather biochar (PFB). In consideration of the crosslinking nature of Ti precursor and keratin, a three-stage method was deployed to develop this biochar. Morphology studies revealed that the PFB was mainly consisted with multilayered graphene like nanosheets, doping with ultrafine TiO 2 nanoparticles homogeneously. Amoxicillin is applied to assess adsorption and photo-degradation abilities. Possessing different functional groups on multilayered graphene oxides like frameworks, the PFB have exhibited excellent adsorption ability and its photo responded region is extended to visible light. Particularly, an extra photo-recyclable behavior was achieved in batch experiments and the reaction mechanism was detected. Up to 80.98% of the absorbability of PFB was reborn after visible light irradiation. The mineralization ability was further studied with total organic carbon (TOC) and mass spectrum (MS) analyses. Besides, considering the cost-free waste feedstocks and easy self-assembling fabrication methods, this photo-recyclable feather biochar is potential in future wastewater treatment. [ABSTRACT FROM AUTHOR]

To improve the photocatalytic efficiency of niobium pentoxide (Nb 2 O 5) for the degradation of organic pollutants, a novel nano-fibriform C-modified Nb 2 O 5 (F–C/Nb 2 O 5) photocatalyst was successfully synthesized by niobium oxalate as precursor and nanofibrillated cellulose (NFC) as template and carbon source. Vacuum induced self-assembly method was used to form the nano-fibriform morphology. Compared to ordinary C/Nb 2 O 5 and commercial Nb 2 O 5 , F–C/Nb 2 O 5 exhibited a typical three-dimensional nanorod structure with plenty of pores. The specific surface area of F–C/Nb 2 O 5 was 3 times that of C/Nb 2 O 5. The prepared F–C/Nb 2 O 5 exhibited a 3.01 eV bandgap and was able to be activated under visible light while that was unable for commercial Nb 2 O 5 with 3.19 eV bandgap. The F–C/Nb 2 O 5 showed the best photocatalytic efficiency in pH value ≤ 3. After cycling for 5 times, the photocatalytic efficiency of F–C/Nb 2 O 5 was still 2.4 times of the ordinary C/Nb 2 O 5 under visible light. Meanwhile, the self-assembly mechanism and photodegradation mechanism were proposed. This study provides a new strategy to form a special nano-fibriform C-modified niobium pentoxide with extremely high photocatalytic efficiency in aqueous solutions. [ABSTRACT FROM AUTHOR]

• Fabrication of C-dots modified 2D-2D heterojunction of BiVO4/Bi3TaO7 was achieved. • C-dots/BiVO4/Bi3TaO7 shows highly stable photocatalytic removal for antibiotics. • C-dot could accelerate electron transport by its good electrical conductivity. • C-dot could extend solar light harvesting by its distinctive up-conversion effect. • C-dots/BiVO4/Bi3TaO7 is potential effective to remove antibiotics in wastewater. Focused on the removal of the complicated residual antibiotic in aqueous environment, in this work, a novel carbon dots (C-dots) sensitized 2D-2D heterojunction of BiVO 4 /Bi 3 TaO 7 were assembled through a simple hydrothermal process. The characteristic by TEM, SEM, and XPS confirmed C-dots evenly anchored on the surface of BiVO 4 /Bi 3 TaO 7 heterojunction. The as-prepared C-dots/BiVO 4 /Bi 3 TaO 7 showed superior performance for the degradation of the various antibiotics under visible light illumination. When the concentration of C-dots in the composite is 3 wt.%, the photodegraded rates are obtained to be 91.7%, 89.3%, 87.1%, for tetracycline (TC), amoxicillin (AMX) and ciprofloxacin (CIP), respectively, without significant deactivation during consecutive ten recycle experiments. Furthermore, by assessing the antibiotics mixture solution of TC, AMX and CIP, it is proposed that the prepared samples are potentially effective for the wastewater effluents. A probable mechanism was reasonably proposed. The improved photocatalytic activities could be attributed to the unique construction of the C-dots mediated heterojunction, which could expedite electron migration, improve light harvesting capacity and enhance charge separation efficiency. The present investigation may provide a new perspective to design C-dots mediated heterojunction which could be a potential visible-light-driven photocatalysts for the better practical applications in remediation of broad-spectrum antibiotic residues. [ABSTRACT FROM AUTHOR]

Abstract This work reports the synthesis of Ag/ZnNb 2 O 6 heterojunctions by solid-state approach followed with the photoreduction of silver. It was found that Ag decorated ZnNb 2 O 6 catalyst was provided with dual roles of silver, including homogeneous doping of Ag ions into ZnNb 2 O 6 host lattice and a large amount of heterojunctions due to the monodispersion of tiny Ag nanoparticles deposited on ZnNb 2 O 6 surface, thereby showing the abnormal visible-light absorption ascribed to the interband introduction and the strong surface plasmon resonance. The photocatalytic effects of silver doping and heterojunctions in visible-light irradiation were investigated, which showed Ag(6 wt.%)/ZnNb 2 O 6 catalyst had the optimal photocatalytic efficiency (96.5–98.2% within 2 h) for the photodegradation of five various dyes and high recyclability during the photocatalytic degradation of methyl orange. Graphical abstract Ag/ZnNb 2 O 6 heterojunctions with dual roles of silver, including doping of Ag ions into ZnNb 2 O 6 matrix and Ag nanoparticles deposited on ZnNb 2 O 6 surface, showed abnormal visible-light degradation ability of dyes. Image 1 Highlights • Ag/ZnNb 2 O 6 heterojunctions show dual roles of silver in surface loading and bulk doping. • The monodispersion of Ag nanoparticles increases the amount of heterojunctions. • The abnormal visible-light absorption is due to the interband introduction and strong surface plasmon resonance. • The heterojunction catalyst exhibits the high efficiency and recyclability for the photodegradation of dyes. [ABSTRACT FROM AUTHOR]

In this work, a series of Au-loaded Na 2 Ta 2 O 6 nanocomposite photocatalysts were prepared via a chemical reduction process. It was observed the tiny Au nanoparticles (∼5 nm) uniformly anchored on the surface of Na 2 Ta 2 O 6 nanoparticles with a well crystallized octahedral morphology. The as-prepared samples demonstrated high efficiency and good recyclability toward reduction of toxic nitrobenzenes to nontoxic aminobenzene. Significantly, a very quickly rate of 2666.7 min −1 g −1 under the simulated solar light irradiation was observed for nitrobenzenes (NB) derivatives reduction. It was found 4-nitrophenol can be completely converted to 4- aminobenzene in only 4 min, 2.35 times higher than that in dark. By evaluate activities over several representative support materials under different reaction conditions, a new photo-synergistic catalytic mechanism was proposed. In the thermocatalytic process, the surface plasmons resonance of Au nanoparticles excited by visible light, and the electron transfer from Na 2 Ta 2 O 6 semiconductor to Au nanoparticle assisted by ultraviolet light, all make the significantly contributions to achieve the efficient reduction of 4-nitrophenol under solar illumination. [ABSTRACT FROM AUTHOR]

In this work, the disordered SnNb x O y with controlled structural distortion was developed in order to uncover the underlying origination for highly enhanced photocatalytic activity of the disordered materials. Synchrotron radiation wide-angle X-ray scattering (SR-WAXS) and transmission electron microscopy (TEM) results indicated that the as-prepared catalysts show disordered features with controlled short range ordering limits. In combination with optical diffuse reflectance spectra, valence band X-ray photoelectron spectroscopy (VB-XPS) and density functional theory (DFT) prediction, the disordered structure engineering can induce continuous band gap broadening and downward valence band edge, predicting enhanced oxidation driving force. Moreover, transient absorption spectroscopy (TAS), electron spin resonance (EPR) spectra suggested that the highly enhanced photocatalytic activity mainly originates from defect-assisted charge separation, which implies that abundant defective centers may serve as trap centers for efficient charge separation and improve charge transfer rate to suppress the charge recombination process. Photocatalytic test demonstrated that the optimal photocatalytic activity toward H 2 evolution of the disordered catalyst shows ∼11.7 times improvement with respect to that of the crystalline counterpart. [ABSTRACT FROM AUTHOR]

AgTaO 3 /AgBr heterojunction was constructed for visible light driven photocatalytic purpose in order to investigate the relevance of phase conversion, electronic structure and photocatalytic properties. The result indicated that AgBr grafted on AgTaO 3 to form AgTaO 3 /AgBr heterojunction gave intense visible light absorption, which exhibits highly enhanced photocatalytic performance than their individual counterpart. Theoretical and experimental investigation showed that the matched electronic structure between AgTaO 3 and AgBr induced an efficient transfer of photogenerated electrons from AgBr to AgTaO 3 , leading to efficient charge separation and the subsequent improved photocatalytic activity. Partial AgBr converted to AgBr/Ag during the photocatalytic process, leading to the construction of ternary AgTaO 3 /AgBr/Ag photocatalyst. Because of the surface plasmon resonance effect of Ag, the resulting AgTaO 3 /AgBr/Ag exhibited wide range absorption and improved charge separation efficiency, which showed high durability and superior photocatalytic activity toward methyl orange degradation. On the basis of spin resonance measurement and trapping experiment, it is expected that photogenerated electrons, O 2 − , and OH active species dominate the photodegradation of methyl orange. [ABSTRACT FROM AUTHOR]

[Display omitted] • A conceptual carbonate mediated hole transfer photocatalytic system is proposed. • carbonates can capture and transfer the photoinduced hole into solution in form of · CO 3 − • Efficient hole capture via carbonates oxidation boosts the charge separation. • The unique · CO 3 −/CO 3 2− shuttle boosting charge separation for enhanced · OH generation. • Enhanced · OH and · CO 3 − generation enables efficient organic pollutants degradation. Inspired by the important role of the manganese enzyme in photo-induced hole transfer of natural photosynthesis, we have developed an innovative carbonate-mediated-hole-transfer strategy for boosting the photocatalytic degradation of organic pollutants. We found that the carbonate species can effectively extract the photo-generated hole in the valence band of carbon nitride to generate · CO 3 − and leaves electron in the conduction band for oxygen reduction to generate · OH. The generated · CO 3 − can be returned to its pristine state of CO 3 2− via the oxidation of organic pollutants. The unique · CO 3 −/CO 3 2− shuttle could largely improve the charge separation via the fast hole extraction that leads to enhanced · OH generation for accelerating the photocatalytic degradation of organic pollutants. As expected, the as-prepared carbon nitride exhibits markedly enhanced photocatalytic performance toward formaldehyde, p-chlorophenol, and phenol degradation than the one without carbonate as additive. The conceptual study demonstrated here may offer new viewpoints in designing high-efficient photocatalytic systems for environmental applications. [ABSTRACT FROM AUTHOR]

In this paper, WO 3 -wrapped NaTaO 3 nanospheres photocatalysts with different W/Ta molar ratios were successfully prepared via a facile hydrothermal method. The samples were characterized by X-ray diffraction, transmission and scan electron microscopy, X-ray photoelectron spectroscopy, FT-IR spectrum, UV−vis diffuse reflectance spectroscopy, and Barrett−Emmett−Teller technique. The photocatalytic activities for degrading tetracycline hydrochloride under visible light irradiation were examined. The results indicated that the as-prepared NaTaO 3 @WO 3 photocatalysts showed the obvious enhancement in the tetracycline hydrochloride degradation ratio, compared with the pure NaTaO 3 and WO 3 under visible light irradiation. The optimum percentage of NaTaO 3 @WO 3 composites with a 60.88% degradation rate was W:Ta = 0.3:1 in mole, which was mainly attributed to the effective separation of the photo-generated electron and hole as well as the expanding of the absorption edge to the visible region due to the spherical heterojunction by wrapping WO 3 on the surface of NaTaO 3 . The radicals trapping experiments demonstrated that there were multiple active species during the degrading process of TC. The possible mechanism of tetracycline hydrochloride degradation by NaTaO 3 @WO 3 composite was also proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • An interlayer confined method is proposed for single atom catalyst construction. • Confining Pt into the interlayer of g-C 3 N 4 endows the it with O 2 resistant property. • A solar energy trigged water-energy-system is proposed for wastewater treatment. • First time achieving pollutant mineralization for H 2 recovery over g-C 3 N 4. Photocatalytic H 2 recovery from organic wastewater degradation has been considered as a promising way to alleviate the energy shortage and to deal with environmental pollution. However, the achievement of H 2 production from organic pollutants mineralization still remains a huge challenge. Herein, a novel solar energy trigged water-energy-system over Pt single atom catalyst (confined by the interlayer subnanospace of carbon nitride, Pt SA /g-C 3 N 4) is proposed, exhibiting remarkable photocatalytic performance toward organic pollutants degradation coupled with hydrogen generation. We found that the well confined interlayer environment not only reduces the H 2 evolution energy barrier to accelerate H 2 evolution, but also blocks the introduced O 2 accessing the interlayer confined Pt atoms. Furthermore, the introduced O 2 could be activated by the surface layers of carbon nitride, which accelerates the mineralization of hole-oxidized pollutants into H 2 O and CO 2. As a result, Pt SA /g-C 3 N 4 exhibits excellent photocatalytic activity toward H 2 production coupled with p-chlorophenol mineralization, where more than 9 μmol of H 2 is generated with the total organic carbon removal reaches 70% within 4 h photocatalysis. The conceptual study shown here may offer new viewpoints in designing high-efficient photocatalyst for environmental related applications. [ABSTRACT FROM AUTHOR]

This work reports on the fabrication of a novel ternary component Ag–Sr 0.25 H 1.5 Ta 2 O 6 ·H 2 O/g-C 3 N 4 photocatalytic system with highly enhanced visible light photocatalytic activity toward Cr(VI) photoreduction and methyl orange degradation. The result indicated that Sr 0.25 H 1.5 Ta 2 O 6 ·H 2 O nanoparticles were deposited on the surface of g-C 3 N 4 with high dispersion and that obtained Sr 0.25 H 1.5 Ta 2 O 6 ·H 2 O/g-C 3 N 4 heterojunction photocatalyst showed strong absorption in the visible light region. The Sr 0.25 H 1.5 Ta 2 O 6 ·H 2 O/50 wt%–g-C 3 N 4 composite displayed increased photocatalytic activity for Cr(VI) photoreduction and methyl orange degradation in comparison with the pristine Sr 0.25 H 1.5 Ta 2 O 6 ·H 2 O and g-C 3 N 4 under visible light irradiation. The matching of the band structure between Sr 0.25 H 1.5 Ta 2 O 6 ·H 2 O and g-C 3 N 4 induced an efficient photogenerated electron transfer from the conduction band of g-C 3 N 4 to the conduction band of Sr 0.25 H 1.5 Ta 2 O 6 ·H 2 O, resulting in efficient separation of the photogenerated electron–hole pairs and the subsequent promotion of photocatalytic activity. Moreover, Ag decorated on Sr 0.25 H 1.5 Ta 2 O 6 ·H 2 O/g-C 3 N 4 can enhance the visible light absorption efficiency and robustly improve the photocatalytic activity by a factor of 4.7 for Cr(VI) photoreduction and 14.2 for methyl orange degradation, respectively. Ag nanoparticles on Sr 0.25 H 1.5 Ta 2 O 6 ·H 2 O/g-C 3 N 4 not only extended the visible light absorption region due to surface plasmon resonance effects, but also acted as an electron mediator as well as an electron acceptor for efficient charge separation. [ABSTRACT FROM AUTHOR]

In this work, we report on the synthesis of a novel ternary component Ag-SrTa 2 O 6 /g-C 3 N 4 photocatalytic system with efficient visible light photocatalytic activity toward Cr(VI) photoreduction and methyl orange degradation. The samples were carefully characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectroscopy, Fourier transformed infrared spectroscopy and photocatalytic test. It is found that SrTa 2 O 6 was deposited on the surface of g-C 3 N 4 and that obtained SrTa 2 O 6 /g-C 3 N 4 heterojunction photocatalyst showed strong absorption in the visible light region. Photocatalytic test indicated that the as-prepared SrTa 2 O 6 /g-C 3 N 4 heterojunction showed increased photocatalytic activity toward Cr(VI) photoreduction and methyl orange degradation in comparison with the bare SrTa 2 O 6 and g-C 3 N 4 under visible light irradiation. The matching of the band structure between SrTa 2 O 6 and g-C 3 N 4 induced an efficient photogenerated electron transfer from the conduction band of g-C 3 N 4 to the conduction band of SrTa 2 O 6 , resulting in efficient separation of the photogenerated electron–hole pairs and the subsequent promotion of photocatalytic activity. Moreover, the decoration of Ag on SrTa 2 O 6 /g-C 3 N 4 led to the formation of ternary component Ag-SrTa 2 O 6 /g-C 3 N 4 photocatalyst, which can highly enhance the visible light absorption efficiency and robustlypromote the photocatalytic activity by a factor of 2.8 for Cr(VI) photoreduction and 4.6 for methyl orange degradation, respectively. Ag decoration on SrTa 2 O 6 /g-C 3 N 4 can not only extend the visible light absorption region due to surface plasmon resonance effects, but also act as an electron mediator for efficient migration of photogenerated electrons and simultaneously prevent the recombination of photogenerated electron–hole pairs as much as possible. Finally, a possible photocatalytic mechanism of the charge transfer in Ag-SrTa 2 O 6 /g-C 3 N 4 photocatalyst was proposed. [ABSTRACT FROM AUTHOR]

In this work, a novel CsTaWO 6 /Au/g-C 3 N 4 hybrid photocatalyst is successfully fabricated. The photocatalytic performance of the heterostructured CsTaWO 6 /Au/g-C 3 N 4 composite was investigated. Au nanoparticles were photo-deposited as the interlayer between g-C 3 N 4 and the surface of CsTaWO 6 , which can facilitate the photoinduced electrons migration as an electron-conduction bridge as well as increase visible-light absorption via the surface plasmon resonance. This heterostructured interface bridging by Au particles may significantly retard the recombination of electron–holes, which is beneficial to promote the photocatalytic activity under visible-light irradiation. It is found the CsTaWO 6 /Au/g-C 3 N 4 sample showed excellent photocatalytic activity of water splitting, even higher than the sum of g-C 3 N 4 and Au/CsTaWO 6 samples, or the sum of CsTaWO 6 and Au/g-C 3 N 4 samples. It indicates that the heterostructured combination of g-C 3 N 4 and CsTaWO 6 bridging by Au particles provided the synergistic photocatalytic activity driving by solar light through an efficient electron transfer process. [ABSTRACT FROM AUTHOR]

In this study, a highly uniform ZnO/NaTaO 3 composite was prepared via simple hydrothermal synthesis. XRD confirmed the composite was constructed by pure cubic phase of NaTaO 3 and hexagonal phase of ZnO. SEM analysis showed that as-prepared ZnO/NaTaO 3 shaped as an irregular ginger with an obviously smaller size than that of pure ZnO without obvious agglomeration. EDS mapping demonstrated that the four elements (Na, Ta, O, Zn) in the composite were very uniformly distributed. The photocatalytic behaviors of as-prepared composites were studied in the degradation of methylene blue both under UV and visible irradiation. The bare ZnO showed the highest activity with 99.8% methylene blue (MB) photodegraded in 70 min under UV light irradiation whereas 94% photodegraded rate was achieved for ZnO/NaTaO 3 . More importantly, the uniform composite of ZnO/NaTaO 3 exhibited effective degradation of methylene blue under visible light which can be attributed to the well dyes adsorption abilities and the high efficiency of electron separation, induced by the synergistic effect between ZnO and NaTaO 3 . It is confirmed the dye rather than a semiconductor is excited under visible light irradiation and a self-sensitized photocatalytic mechanism was then proposed based on the experimental results. [ABSTRACT FROM AUTHOR]

Au/ZrO 2 nanoparticles have been widely used as photocatalysts in various organic syntheses because of their localized surface plasmon resonance (LSPR) effects. In our work, Au/ZrO 2 has been synthesized by a solution method and it was used as a heterogeneous catalyst in the synthesis of imines from alcohols and aniline with irradiation by visible light. The reaction occurred in two steps: step 1 was the aerobic oxidation of the alcohols and step 2 was the nucleophilic addition of aniline. Dimethyl sulfoxide (DMSO) was used as a solvent in the reaction. The selectivity in the synthesis of imines over 3 wt% Au/ZrO 2 (with mean particle size of 5 nm) was high (over 90%) with irradiation by visible light at room temperature, and an obvious difference in the conversion was observed between the reactions with light irradiation and those without light. The intensity and wavelength of the light strongly affected the reaction. The Au/ZrO 2 could be used at least 5 times. A reaction mechanism was proposed based on the experimental results. The results indicate that the reaction of alcohols and aniline using Au/ZrO 2 as the photocatalyst can proceed under mild conditions. Furthermore, this process is environmentally friendly and green. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bimetal SA catalysts are prepared via PH 3 -induced annealing method using soft-templates as precursors. • Dual-active sites synergistically affect the electron structure via P bridging. • Fe-P-Ni can activate Fe sites via donating electrons from Ni to Fe. • One-step defluorination can be achieved by CN-FeNi-P during enoxacin degradation. Understanding of synergistic mechanisms on bimetal single atom catalysts is a vital basis to design and synthesize effective catalytic materials. A bimetal of Fe and Ni anchored carbon nitride (CN-FeNi-P) is prepared by PH 3 -induced annealing method using soft-template precursors. Experimental results show that the coordination sites of Fe/Ni-N 4 P 2 are uniformly distributed on the carbon nitride, and a structure of Fe-P-Ni is formed at the second shell via P bridging. Herein, Fe-dominated active sites are formed by the interaction between Fe and Ni single atoms in CN-FeNi-P. Benefitting from the synergistic effects, the CN-FeNi-P exhibits a high efficiency electron utilization, achieving 100% of enoxacin degradation under visible light irradiation within 40 min. In addition, it achieves 58% of defluorination rate which is rarely mentioned in others. The facile method expands to other single atom catalysts in photocatalysis and electrolysis, and this work provides a new insight into understanding synergistic mechanisms of bimetal single atom catalysts. [ABSTRACT FROM AUTHOR]

Abstract: TiO2 nanoparticles were prepared using a surfactant (linoletic acid (LA) or polyethylene glycol-400 (PEG-400)) at various hydrolysis ratios (R=H2O/C2H5OH) by the hydrothermal method and studied for photocatalytic degradation of rhodamine B (RhB) under visible light irradiation. Special shapes of TiO2 nanoparticles, such as cubic, hexagon, bipyramid, and bullet, were found from the use of PEG-400 during the preparation. The cause for the formation of these special shapes is also discussed here. Interestingly, the hydrolysis ratios affected the Brunauer–Emmett–Teller (BET) special surface areas of the TiO2 nanoparticles. Owing to the effects of the surfactant PEG-400 on the microstructures, the resulting materials exhibited relatively higher photocatalytic activity than conventional TiO2 nanoparticles in the presence of LA. Furthermore, P-TiO2-8/10 (P is PEG-400 and 8/10 is H2O/C2H5OH molar ratio) nanoparticles had a similar photocatalytic activity to P25 and TiO2-10/10. [Copyright &y& Elsevier]

Abstract: The photodegradation of sulforhodamine B on vanadium-doped TiO2–montmorillonite (TiO2–MMT) nanocomposites was investigated under visible light irradiation. V-TiO2–MMT nanocomposites with different amounts of MMT were prepared by a sol–gel process. The microstructure and properties of V-TiO2–MMT were characterized by XRD, TEM, XPS, DRS, nitrogen adsorption isotherms, and FTIR. These analytic results indicated that the different Ti/MMT ratios exerted a great influence on their microstructures and their photocatalytic activities. The average sizes of V-TiO2–MMT were smaller than those of pure TiO2 and V-TiO2. And the layered structure of MMT was completely destroyed in the V-TiO2–MMT with the relatively high ratio of Ti/MMT (240, 120, 80, 60mmol/g), but it retained the partial MMT layered structure and had an enlargement of some basal space of MMT in V-TiO2–MMT with the relatively low ratio of Ti/MMT (30, 24mmol/g). V-TiO2–MMT/120 (120 denotes the ratio of Ti/MMT is 120mmol/g. The names of other catalysts followed the same convention.) and V-TiO2–MMT/30 had relatively higher photocatalytic activity in comparison to the others. Besides, in the preparation process, we selected V-TiO2–MMT/120 using different washing media to examine the effect of washing medium on the photocatalytic activity. The result indicated that it was critical to choose a proper washing medium to obtain an optimal photocatalytic activity. [Copyright &y& Elsevier]