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Converting CO2 into valuable solar fuels through photocatalysis has been considered a green and sustainable technology that is promising for alleviating global warming and providing energy in an environmentally friendly manner. However, traditional photocatalysts generally suffer from low surface-reactive reaction sites, inefficient light harvesting and rapid recombination of electron–hole pairs. Lead halide perovskite materials have been considered ideal semiconductor photocatalysts for photocatalytic CO2 reduction due to their tunable band gaps, strong light absorption, and low cost. Herein, a series of L2Csn−1PbnX3n+1 (L = ba, ha, oa; X = Cl, Br, I; n = 1, 2) 2D layered perovskites were synthesized by a facile solvothermal method. The effects of alkyl amine chain length, halogen atoms and inorganic layer number on their properties were studied. More importantly, these 2D materials were used as photocatalysts for CO2 reduction without any sacrificial agents. These 2D perovskites exhibited markedly increased performance in comparison with 3D bulk materials, benefitting from the larger surface-area-to-volume ratio and faster and more efficient exciton dissociation, which achieved the highest CO yield of 158.69 μmol g−1 h−1 and CH4 yield of 6.9 μmol g−1 h−1 through the design of the photocatalytic system. In addition, the influence of light source conditions on photocatalysis was studied systematically, including light source intensity and wavelength. The experimental results indicated that an appropriate solvent, high light intensity and monochromatic light source matching the wavelength of exciton absorption can effectively improve the photocatalytic efficiency. [ABSTRACT FROM AUTHOR]

Improving the separation rate of electron-hole pairs by doping ion is an effective means to enhance photocatalytic activity and has aroused research interest in the development of high-efficient photocatalytic materials. To promote the degradation performance of organic pollutants like Rhodamine B (RhB) under visible light irradiation (λ > 420 nm), an Fe3+ doped bismuth molybdate (Fe–Bi 2 MoO 6) composite photocatalyst was synthesized using a simple hydrothermal technique. When the doping amount of Fe3+ was 1 wt%, the composite represented the highest photocatalytic activity with 92.4% RhB removal after 90 min of visible light irradiation, which was 66.3% higher than pristine Bi 2 MoO 6 nanosheets. Trapping experiments and EPR measurements proved that the holes (h+) and superoxide radical (•O 2 −) were the primary reactive species. Additionally, the introduction of Fe3+ broadened the light absorption range and acted as an n-type impurity to increase the electron density of Bi 2 MoO 6 nanosheets, resulting in improved photocurrent density, increasing carrier capture and prolonging carrier lifetime. Moreover, the Fe–Bi 2 MoO 6 composite had good stability, with its removal rate remaining at 83.2% after four cycles of reuse. The novel Fe–Bi 2 MoO 6 composite photocatalyst was formulated with the aim of realizing a practical method to remove organic pollutants using solar light. [ABSTRACT FROM AUTHOR]

Abstract The potential of TiO 2 -based photocatalysts in mitigating the effects of environmental pollutants is evident in the scientific literature but the large-scale implementation of photocatalytic concretes still appears limited, despite the current global concerns over urban NOx pollution. Improvements in cost-effectiveness are required to enhance the case for a photocatalyst-modified infrastructure and this must address catalyst efficiency, catalyst loading and performance durability. This paper compares photocatalytic efficiencies of supported TiO 2 on mortar surfaces with the more conventional TiO 2 dispersed in mortar. The influences of environmental conditions, such as NO concentration and flow rate, UVA light intensity and relative humidity, on photocatalytic performance are also investigated using photonic efficiency as an indicator. The supported TiO 2 shows greater degradation of NOx (De-NOx), at about 9 times higher than TiO 2 powder dispersed in the mortar, ca. 150 times higher utilization efficiency, than that of TiO 2 in traditional photocatalytic mortar (with 5% loading). Graphical abstract Unlabelled Image Highlights • Supported TiO 2 shows greater utilization efficiency than that of TiO 2 in mortar. • Binding durability of supported TiO 2 in mortar surface depends on its exposed depth. • Environmental conditions influences on photocatalytic performance are presented. • NO concentration, flow rate and relative humidity are main factors to NOx removal. [ABSTRACT FROM AUTHOR]

To improve the photocatalytic performance and utilization of TiO 2 particles in cementitious materials, this work investigated and differentiated the influences of cement substrate pore structure and TiO 2 particles loading level on photocatalytic degradation of gaseous benzene. It is noted that TiO 2 particles have different loading behaviors on various density cement substrates surface. Low density cement substrates are useful to disperse the loaded TiO 2 particles due to the loose network pores of needle like hydrates, while high density substrates can cause the agglomeration of loaded TiO 2 particles. The photocatalytic performance results reveal that sample with ca. 0.8 g/cm 3 design density has the highest photocatalytic performance. However, TiO 2 loading concentration can also affect its agglomeration degree, which shows that the loaded TiO 2 particles gradually form the agglomerates with the increase of loading concentrations. The photocatalytic performance for degradation of gaseous benzene increases as increasing TiO 2 loading amounts, and then become to steady, suggesting that the optimum TiO 2 loading concentration (1.0 g/L) can allow the best utilizations of TiO 2 particles on porous cement surface. [ABSTRACT FROM AUTHOR]

A low cost zeolite fly ash bead/TiO 2 (ZFABT) composite materials with various surface structure features were prepared for describing those structures importance on TiO 2 coating, adsorbability and photocatalytic performances. The results indicated that fly ash bead (FAB) surface was significantly altered by the precipitation/growth of secondary zeolite phases after alkali activation, which generates abundant open pores and stacked petal-liked spherical beads (∼2 μm, Sodalite zeolites). More importantly, this porosity increases as activation time was increased from 2 h to 12 h, through the precipitation of sodalite and then Na-P1 (lamellar crystals) and Na-X (octahedral crystals) zeolite structures. Compared to those of unsupported TiO 2 or inactivated support/TiO 2 samples, all of ZFABT samples exhibited a higher adsorption capacity and photocatalytic efficiency for RhB removal. However, adsorption is not only one factor to influence TiO 2 surface reaction, the intraparticle diffusion rate of rhodamine B (RhB) molecules, and light penetration are also important parameters. Alkali activated 4 h ZFABT sample exhibited the highest photocatalytic activity, indicating its pore structure provided a better balance for those parameters to achieve a synergistic adsorption/photocatalytic process. The kinetics model suggested its high intraparticle diffusion rate allowed for more RhB molecules to easily reach the reaction surface, which is more important for high efficiency photocatalysis. [ABSTRACT FROM AUTHOR]

This study investigated the strategy of using zeolite fly ash bead (ZFAB) as a carrier of TiO 2 photocatalyst to improve the photocatalytic efficiency and long-term performance of photocatalytic cementitious materials. Various photocatalytic cementitious specimens with different ZFAB/TiO 2 dosages were prepared by surface sprayed and intermixed methods. Their characteristics and photocatalytic effects were evaluated. It was found that ZFAB could improve the exposure degree of TiO 2 particles in cement matrix surface, and the exposure contents were dependent on ZFAB/TiO 2 incorporation methods and dosages. The photocatalytic results showed that all ZFAB/TiO 2 applied cementitious samples performed better photocatalytic effects and long-term performance than that of samples prepared with pure TiO 2 . Moreover, the photocatalytic effects increased with the increase of ZFAB/TiO 2 dosages, and ZFAB/TiO 2 surface-sprayed samples displayed better effects than that of ZFAB/TiO 2 inter-mixed samples. These results indicates that ZFAB is useful to enhance the photocatalytic efficiency of TiO 2 in cementitious materials, which could reduce the cover risks of cement hydrates on TiO 2 particles, and improve its dispersibility and exposure degree as well. Thus, the use of ZFAB could provide a potential method for high efficiency and long-term application of TiO 2 in construction field. [ABSTRACT FROM AUTHOR]

Visible-light-driven Ag/AgBr/TiO2/activated carbon ( AC) composite was prepared by solgel method coupled with photoreduction method. For comparison, TiO2, TiO2/ AC, and Ag/AgBr/TiO2 were also synthesized. Their characteristics were analyzed by XRD, SEM- EDS, TG- DSC and UV-vis techniques. Photocatalytic activity and antibacterial performance under visible-light irradiation were investigated by ICP- AES, ATR- FT- IR and spectrophotometry methods using methylene blue and Escherichia coli as target systems, respectively. The results showed that Ag/AgBr was successfully deposited on anatase TiO2/ AC surface, and exhibited a distinct light absorption in the visible region. Ag/AgBr/TiO2/ AC displayed excellent antibacterial performance both in dark and under visible-light illumination. The growth of E. coli cell was inhibited in the presence of Ag/AgBr/TiO2/ AC in dark. Moreover, upon visible-light illumination, a significant damage of cell membrane was noticed. Ag/AgBr/TiO2/ AC was also shown higher photocatalytic efficiency for methylene blue degradation than those of TiO2, TiO2/ AC, and Ag/AgBr/TiO2. This is attributed to the synergetic effect between AC and Ag/AgBr/TiO2, of which AC acts as the role of increasing reaction areas, continuous enriching, and transferring the adsorbed MB molecules to the surface of supported photocatalysts, and the Ag/AgBr/TiO2 acts as a highly active photocatalyst for degrading MB molecules under visible-light irradiation. [ABSTRACT FROM AUTHOR]

By using redox-active nickel(II) ions as the connect nodes, a hexanuclear metal-organic cylinder (Ni-YL) was achieved through self-assembly with a large cavity and an opening windows capable to accommodate guest molecules. The suitable cavity of Ni-YL provides an opportunity to encapsulate the anionic ruthenium bipyridine derivative [Ru(dcbpy)3] (dcbpy=2,2′-bipyridine-4,4′-dicarboxylic acid) as the photosensitizer for light-driven reactions. The host-guest behavior between Ni-YL and [Ru(dcbpy)3] was investigated by mass spectrometry, NMR spectroscopy, and computational studies, revealing an effective binding of the guest [Ru(dcbpy)3] within the cavity of Ni-YL. Optical experiments suggested a pseudo-intramolecular photoinduced electron transfer (PET) process between the [Ru(dcbpy)3] and the host Ni-YL, leading to an efficient light-driven hydrogen production based on this system. Control experiments with a mononuclear Ni complex as a reference photocatalyst and the inactive [Fe(dcbpy)3] as an inhibitor for comparison were also performed to confirm such a supramolecular photocatalysis process. [ABSTRACT FROM AUTHOR]

Photocatalytic expanded shale (PES) and photocatalytic exposed aggregate concrete (PEAC) were prepared to improve the utilization ratio, photocatalytic effect and long-term catalytic performance of TiO 2 in cementitious materials. Their physicochemical properties, photocatalytic performance were studied in details. It was found that the photocatalytic removal rate of benzene on PES significantly increased with the increase of TiO 2 coating concentration and the expanded shale porosity. Although the decrease of photocatalytic effect was inevitable when PES was mixed into concrete, the prepared PEAC still revealed a higher catalytic activity compared with the concrete prepared by using photocatalytic limestone coarse aggregate. This was attributed to the surface retarder spraying in the preparation of PEAC, which could weak the adverse influence of cement on TiO 2 . Moreover, due to the good exposure of TiO 2 and the formation of stable chemical bond on expanded shale surface, the photocatalytic effect of PEAC still exceeded 80% after 10 months. The results suggested that the novel strategy of enhancing photocatalytic efficiency of TiO 2 in cementitious materials was facilely realized by the preparation of PES and PEAC, which could provide more TiO 2 active sites, high specific surface areas, more gas diffusion and light transmittance channels, thus improving the reacting areas and utilization rate of TiO 2 . [ABSTRACT FROM AUTHOR]

Highlights: [•] The hierarchical porous FMOC substrate with good light transmittance was prepared. [•] Through a facile method synthesized FMOC/TiO2 catalyst with desirable microstructure. [•] Hierarchical structure provided more active TiO2 sites and large catalysis areas. [•] Reaction rate of FMOC/T12 was estimated to be about 3.87 times higher than MOC/T12. [•] TiO2 exhibited an excellent re-use performance on surface of porous magnesium cement. [Copyright &y& Elsevier]

Abstract: A series of photo-catalysts were synthesized by neodymium and fluorine doped TiO2, and their characteristics evaluated by X-ray diffraction (XRD), UV–vis diffuse reflectance spectra (UV–vis), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Neodymium and fluorine doped TiO2 has obvious absorption in the visible light and the absorption edge shifts toward red wavelength. In addition, compared with pure TiO2, the doped catalyst has intense absorption at 528, 587, 750, 808, and 881nm. The catalytic efficiency was tested by monitoring the photo-catalytic degradation of methylene blue (MB) in visible light and ultraviolet light. The results showed that the optimum doping content was Nd:F:TiO2 =0.5:5:100 (molar ratio) heat treated at 500°C, and the reaction rates of MB degradation were estimated to be about 1.76 times and 1.45 times higher than undoped TiO2 in ultraviolet light and visible light. [Copyright &y& Elsevier]

Abstract: A series of photocatalysts were synthesized by neodymium and iodine doped TiO2. The characteristics of neodymium and iodine doped TiO2 were evaluated by X-ray diffraction (XRD), UV–vis diffuse reflectance spectra, and scanning electronic microscope (SEM). In the synthesis process, Nd:I:TiO2 with different doping content (molar ratios) calcined at different temperature was designed. After the photocatalysts were synthesized under different condition, they were compared with each other by photocatalytic degradation of methylene blue (MB). The most efficient catalyst to degrade MB was Nd combined with I doped TiO2 with molar ratio of 5:10:100 calcined at 400°C. It is anatase crystal and the average size of crystallites was about 6.0nm. It has absorption spectrometry in the visible light range of 400–550nm. In addition, compared with pure TiO2, the doped catalyst also has intense absorption at 528, 587, 683, 750, 808, and 881nm. The catalytic efficiency was tested by monitoring the photocatalytic degradation, and detriment of MB and bovine serum albumin (BSA). The antibacterial activities were studied by Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The results showed that the optimum doping contents was Nd:I:TiO2 =5:10:100 (molar ratio) calcined at 400°C, and the synthesized catalyst could inhibit E. coli and S. aureus through damaging their outer membrane (even deteriorated completely) by the irradiation of visible light. [Copyright &y& Elsevier]

The key to realizing efficient hydrogen production driven by sustainable solar is to develop high performance photocatalysts. Herein, a ZnIn 2 S 4 /Cu-doped WO 3 ·0.5H 2 O (ZIS/Cu-WO) heterojunction was synthesized and the synergy between Cu doping and Z-scheme heterojunction in hydrogen production was explored. The synthesized (ZIS/Cu-WO) has a special octahedral structure. The doping of Cu ions can induce the localized surface plasmon resonance (LSPR) of WO 3 ·0.5H 2 O, which extends the spectral response range and improves charge conduction. After growing ZnIn 2 S 4 (ZIS), the optimal ZIS/Cu-WO photocatalyst shows a remarkable H 2 production rate of 3084 μmolg-1h-1, which is 7.0 times than undoped ZnIn 2 S 4 /WO 3 ·0.5H 2 O (ZIS/WO). The enhanced photocatalytic hydrogen production performance is attributed to the synergistic effect of Cu doping and Z-scheme heterojunction, which further accelerated the separation of photogenerated electron holes. Moreover, the Z-scheme photogenerated charge transfer mechanism was confirmed, and the ZIS/Cu-WO heterojunction exhibits superior stability in 16 h cycle test. This study provides a valuable reference in designing metal ion-doped heterojunction photocatalysts. [Display omitted] • Cu doping can accelerate the charge generation and transfer in ZnIn 2 S 4 /Cu-WO 3. • Cu doping induces the localized surface plasmon resonance (LSPR) effect in WO 3. • Synergy between Cu doping and heterojunction improves photocatalytic performance. [ABSTRACT FROM AUTHOR]

Photo‐assisted uranium reduction from uranium mine wastewater is expected to overcome the competition between impurity ions and U(VI) in the traditional process. Here, B‐TiO2@Co2P‐X S‐scheme heterojunction with metal‐oxygen‐hydrogen (M‐O‐H) is developed insitu modification for photo‐assisted U(VI) (hexavalent uranium) reduction. Relying on the DFT calculation and Hard‐Soft‐Acid‐Base (HSAB) theory, the introduction of metal‐oxygen‐hydrogen (M‐O‐H, hard base) metallic bonds in the B‐TiO2@Co2P‐X is found to enhance the hydrophilicity and the capture capability for uranyl ion (hard acid). Accordingly, B‐TiO2@Co2P‐500 hybrid nanosheets exhibit excellent U(VI) reduction ability (>98%) in the presence of competing ions. By self‐consistent energy band calculations and in‐situ KPFM spectral analysis, the formation of the internal electric field between B‐TiO2 and Co2P at the heterojunction is proven, offering a strong driving force and atomic transportation highway for accelerating the S‐scheme charge carriers directed migration and promoting the photocatalytic reduction of uranium. This work provides a valuable route to explore the functionally modified photocatalyst with high‐efficiency photoelectron separation for U(VI) reduction. [ABSTRACT FROM AUTHOR]

• A novel strategy is developed to achieve perovskite phase transformation at low temperature. • La 1.33-x Na 3x Ti 2 O 6 /Na 3 La 2 (BO 3) 3 composites were synthesized. • The crystalline degree of perovskite structure evolves with ratio of Na+ ions in A site. • Enhanced optical absorption and intimate interface contact were achieved. • The composites possess enhanced photocatalytic H 2 evolution activity under visible light. Perovskite-type oxide semiconductors, as promising photocatalysts, possess flexible structures with corner-shared BO 6 octahedrons and A cations, but are limited by the broad band gaps and severe photo-induced carrier recombination. Herein, a series of La 1.33-x Na 3x Ti 2 O 6 /Na 3 La 2 (BO 3) 3 composites were synthesized by annealing the layered La 2 Ti 2 O 7 with NaBH 4. The doping of Na+ ions in perovskite's A-site promotes the transformation of La 2 Ti 2 O 7 into La 1.33-x Na 3x Ti 2 O 6 phase, meanwhile, substituted La species turn into Na 3 La 2 (BO 3) 3 phase. The crystalline degree of perovskite structure evolves with the ratio of Na+ ions in the A site, and La 2 Ti 2 O 7 undergoes amorphization, recrystallization, and further decomposition as the Na species increases. In well-crystallized La 1.17 Na 0.48 Ti 2 O 6 /Na 3 La 2 (BO 3) 3 , intimate interfacial contacts induce extended optical absorption and optimized charge transfer. Under visible light irradiation, the sample exhibits significantly enhanced photocatalytic H 2 evolution activity, with hydrogen production rate reaching 660 μmol∙g−1·h−1, whereas La 2 Ti 2 O 7 has almost no catalytic activity. This work presents a novel strategy to transform the perovskite oxides at a relatively low temperature by exchanging cations with reductive NaBH 4. It demonstrates applications in the development of visible light-driven perovskite-based heterogeneous photocatalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel approach for in-situ encapsulating the Fe-O clusters in ZIF-L (xFe-O@ZIF-L) has been developed. • Productive photocatalytic Cr(VI) reduction is achieved by xFe-O@ZIF-L under neutral conditions. • xFe-O@ZIF-L shows greatly enhanced photocatalytic activity to the original ZIF-L. • Mechanisms for Cr(VI) reduction by xFe-O@ZIF-L are proposed. Photocatalytic reduction of Cr(VI) in non-acidic circumstances has been an essential problem in the recent research of wastewater treatment. In this study, unique xFe-O@ZIF-L photocatalysts were synthesized with the assistance of mannitol. Fe-O clusters were in-situ encapsulated into the cavities of ZIF-L via this method. The morphology, optical response, electrochemical properties, and Cr(VI) degradability of as-synthesized photocatalysts were investigated. Several experiments demonstrated that the addition of Fe-O clusters considerably expanded the photo-response range while also enhanced photogenerated electron usage through the redox cycling of Fe sites. The micro-mesoporous structure in hybrid samples provides better conditions for mass transfer and exposure of reaction sites. Benefiting from the incorporation of Fe-O clusters, the hybrid material showed improved photocatalytic Cr(VI) reduction ability. After 90 min illumination, the optimum sample with a dosage of 0.5 mg/mL achieved an 86.6% degradation rate of 30 mg/L K 2 Cr 2 O 7 solution even under neutral conditions. The reaction rate constant of the optimum sample (0.0210 min−1) can be up to 105 times that of the original ZIF-L (0.0002 min−1). This innovative hybrid xFe-O@ZIF-L photocatalysts offer a fresh strategy for the photocatalytic treatment of non-acidic Cr(VI)-containing wastewater. [ABSTRACT FROM AUTHOR]

Porous magnesium oxychloride cement (PMOC) has a high specific surface area formed by interlocking whiskers, which can be used as a promising photocatalyst substrate for the photocatalytic removal of atmospheric pollutants. In this paper, magnesium oxychloride cement (MOC) was used as matrix and TiO2 as catalyst to prepare MOC blocks. Plant-based protein was used as a foaming agent to form the layered porous structure suitable for supporting TiO2 particles, which effectively increased the surface area of light radiation and TiO2 adhesion area in photocatalytic porous magnesium oxychloride cement (PPMOC). It was found that the addition of the foaming agent can increase the adsorption capacity of MOC to TiO2. The vacuum-immersion loading method can effectively support TiO2 on the surface of PMOC. The photocatalytic performance of PPMOC can be improved by multiple loading, while higher porosity of PMOC would reduce the loading surface of matrix to TiO2 particles, which might decrease the photocatalytic efficiency. As can be observed in PPMOC specimens, when the porosity of PPMOC is less than 60%, increasing the porosity can improve the photocatalytic efficiency, while when the porosity is higher than 60%, increasing the porosity decreased the photocatalytic efficiency due to the reduction of the loading surface. The excellent nitrate selectivity of PPMOC also shows good application potential in the field of catalytic degradation of nitrogen oxides. [ABSTRACT FROM AUTHOR]

The development of innovative, low-cost, and effective photocatalysts for the degradation of organic pollutants is critical for wastewater treatment. Herein, a novel spindle-shaped BiVO 4 was prepared to construct direct ZnIn 2 S 4 /BiVO 4 Z-scheme heterojunction photocatalysts for the first time. The compositions, microscopic structure, optical and electrochemical properties of nanocomposites were studied. Moreover, the degradation performance to tetracycline hydrochloride was tested to evaluate the photocatalytic property of prepared samples. The results revealed that the degradation rate of the optimal sample reached 93.3% after 2 h of light exposure, which is 2 and 2.5 times higher than that of pure ZnIn 2 S 4 and BiVO 4 , respectively. The higher photocatalytic activity was ascribed to the increased charge carrier separation and migration efficiency provided by the unique Z-scheme structure of the ZnIn 2 S 4 /BiVO 4. The quenching experiments indicated that h+ and · O 2 - served as the main active species in the process of photocatalytic degradation. Hence, the excellent catalytic activity of ZnIn 2 S 4 /BiVO 4 provides a new method for the elimination of organic pollutants in the environment. [Display omitted] [ABSTRACT FROM AUTHOR]

Photocatalytic degradation of organic contaminants has recently been a prominent topic in wastewater remediation. The present work reports on the synthesis of novel 2D/2D Bi 2 WO 6 /ZnIn 2 S 4 heterojunction photocatalytic composite materials by simple electrostatic self-assembly of ZnIn 2 S 4 and Bi 2 WO 6 nanosheets. The photocatalytic degradation of tetracycline hydrochloride (TC-HCl) was used to assess the performance of the as-prepared samples. Bi 2 WO 6 /ZnIn 2 S 4 nanocomposites showed enhanced activities, and the optimized sample (BWO/ZIS-50) had the greatest reaction rate constant (2.303% min−1), 2.4 and 2.2 times that of pristine Bi 2 WO 6 and ZnIn 2 S 4. The photocatalytic activity was increased because of better light absorption and faster photogenerated carrier separation/migration via the Z-scheme mechanism. This research is anticipated to make a contribution to the design and synthesis of 2D/2D Z-scheme nanocomposites for photocatalytic wastewater treatment. [Display omitted] • 2D/2D Bi 2 WO 6 /ZnIn 2 S 4 heterojunction was prepared via electrostatic self-assembly. • The coupling of Bi 2 WO 6 and ZnIn 2 S 4 triggered enhanced photocatalytic TC-HCl degradation performance. • Z-scheme mechanism was verified for the Bi 2 WO 6 /ZnIn 2 S 4 photocatalytic system. [ABSTRACT FROM AUTHOR]

• BiVO 4 nanotubes was synthesized by a template-free approach. • BiVO 4 nanotubes exhibited high visible light absorption capacity. • Excellent photocatalytic degradation performance of TC-HCL was achieved. The development of hollow tubular nanostructured photocatalysts has been identified as a research priority in the realm of photocatalysis. However, fabricating bismuth vanadate (BiVO 4) nanotubes, which are effective photocatalysts for water purification, remains challenging. The present work effectively produced uniform single-phase BiVO 4 nanotubes using a template-free approach. As a consequence of the unique hollow tubular structure, the prepared sample exhibited a high visible light absorption capacity and a large specific surface area, which improves photocatalytic efficiency. Within 120 min, a degradation rate of up to 70% of tetracycline hydrochloride was reached under visible light. This study will enrich the morphological diversity of BiVO 4 photocatalyst and promote the development of BiVO 4 -based photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple but versatile method was constructed for structure parameter controlled mesoporous ceria nanoparticles synthesis. • The oxygen storage capacity of mesoporous ceria nanoparticles is mainly controlled by their pore size and crystallite size. • The oxidase mimetic activity of mesoporous ceria nanoparticles was determined by their pore size when TMB was used as substrate. • The photocatalytic activity of mesoporous ceria nanoparticles dominated by their surface area when AO7 was used as substrate. Mesoporous ceria nanoparticles (MCNs) have many superiorities such as higher surface area and more active reaction sites over their solid counterparts. However, the correlation between their structure and catalytic activity is poorly understood due to the lack of methods to synthesize MCNs with variable and well-defined structure parameters. In this study, a MCNs synthesis platform featured with strong structure parameter tuning capacity was established to synthesize plenty of MCNs for exploring their structure-catalytic activity relationship. The platform was composed of Ce(NO 3) 3 ·6H 2 O precursor, trioctylphosphine oxide (TOPO) ligand, and ethanol and octadecene (ODE) solvent. Through altering ligand/precursor ratio, ligand-precursor addition manner and reaction temperature, three groups of MCNs, totally twelve nanoparticles, were synthesized on the platform. The structure parameters of the synthesized MCNs were collected, and their catalytic activities including oxygen storage capacity (OSC), oxidase mimetic activity and photocatalytic activity were evaluated. The MCNs demonstrated wide range of nanoparticle diameter (40–115 nm), pore diameter (2.09–4.17 nm), pore volume (0.20–0.40 cm3 g−1), surface area (119.2–202.8 m2 g−1), and crystallite size (8.8–9.95 nm). These parameters played different roles in controlling different catalytic reactions, where pore size and crystallite size determined the oxygen storage capacity (OSC), pore size regulated the enzyme mimetic activity, and surface area dominated the photocatalytic activity. This study provided important insights into the correlation between structure and catalytic activity of MCNs, which was critical to the fabrication of MCNs based catalytic reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • This review works on the non-metal modified g-C 3 N 4 catalysts. • The structural changes and catalytic properties of these catalysts are discussed. • Recent advances of these catalysts based applications are summarized. • The development of current bottlenecks and future directions are proposed. Over the past few decades, graphitic carbon nitride (g-C 3 N 4) has gained increasing interest due to its unique and excellent properties. To improve its inherent drawbacks and perfect its catalytic performance, many convenient and facile strategies have been developed, including metal and non-metal modifications. However, the low content in nature and the leaching of toxic metals in photocorrosion have been two critical obstacles for metal-based photocatalysts in practical applications. Therefore, it is increasingly urgent to develop and design efficient and stable non-metal modified g-C 3 N 4 -based photocatalysts. Here, this review begins with a brief presentation of the unique characteristics of g-C 3 N 4. Then, to maintain the metal-free nature of g-C 3 N 4 , the four most frequently used modification strategies are discussed, including vacancies introduction, doping with non-metal elements, modifying with non-metal quantum dots and coupling with other semiconductors. In addition, the latest developments of non-metal modified g-C 3 N 4 -based photocatalysts for energy-related and environmental applications are systematically discussed. In the end, both the current development bottlenecks and future development directions of g-C 3 N 4 -based metal-free photocatalysts are presented. Basically, we highlight the unique properties of completely non-metal modified g-C 3 N 4 , which has positive implications for the sustainable development of g-C 3 N 4 -based non-metal photocatalysts. Furthermore, we hope that it can spark new ideas and present promising directions to design metal-free photocatalysts for energy-related and environmental applications. [ABSTRACT FROM AUTHOR]

Photocatalytic cementitious material (PCM) was prepared by porous magnesium oxychloride cement (PMOC) and TiO 2 photocatalyst. Influences of PMOC substrate surface microstructure on TiO 2 loading and photocatalytic performance had been investigated. The results revealed that loading effect mostly depends on PMOC substrate surface microstructure which could be controlled by its curing age. Appropriate interlaced microstructure enhanced TiO 2 dispersity, loaded mass and adsorption capability. PCM-14d specimen (14-day curing before TiO 2 loading) had the best photocatalytic performance, which could completely purify toluene (200 ppm) within 80 min. Practical simulation experiment indicated that PCM-14d specimen was 1.3 times better than nickel foam based photocatalytic material. [ABSTRACT FROM AUTHOR]

The development of new catalysts that exhibit catalytic activity and enhance the catalysis under light-irradiation could help eliminate the barrier between traditional catalysts and photocatalysts. Herein, an organic-inorganic hybrid Anderson-type polyoxometalate (noted as POM 1) was synthesized by incorporating a [MnMo 6 O 18 ] cluster and two rare three-coordinated copper sites, which were connected by the organic [(OCH 2) 3 CN CH-4-Py] (Py ​= ​pyridine) moieties on both sides. The resultant POM 1 exhibited an enhanced luminescence property compared with the free [MnMo 6 O 18 ] cluster. While in terms of photocatalytic activity, the prepared catalyst exhibited an excellent selective degradation ability toward a positive-charged methylene blue dye in an aqueous solution. Meanwhile, the X-ray photoelectron spectrometry analysis indicated the coexistence of Cu(I)/Cu(II) ions and suggested that the partly oxidized Cu(II) ions in 1 could be reduced to Cu(I) ions via the photoinduced electron transfer from the [MnMo 6 O 18 ] unit. This in-situ reduction process provides an enhanced heterogeneous catalytic performance in terms of azide-alkyne cycloaddition, affording almost complete conversion within a 4 ​h irradiation using a 20 ​W household incandescent lamp as the light source at room temperature under solvent-free conditions. A new linear Anderson-based polyoxometalate (POM) was synthesized by the functionalized [MnMo 6 O 18 ] unit and Cu(I/II) ions with a rare triangular configuration. This POM could occur an in-situ reduction process under light irradiation and thus exhibits the enhancing heterogeneous catalytic performance towards azide-alkyne cycloaddition. [Display omitted] • A new linear Anderson-type polyoxometalate (POM) with three-coordinated copper ions has been synthesized. • This material act as efficient heterogeneous catalyst for azide–alkyne cycloaddition under visible-light irradiation. • The enhanced photocatalysis attributes to a in-situ reduction process via the photoinduced electronic transfer from POM to copper ions. [ABSTRACT FROM AUTHOR]

Abstract: An original ultrasound (US) directly intensified photocatalytic reactor was designed to degrade azo dye pollutant methyl orange (MeO) using Degussa TiO2 as the photocatalyst. The sonolytic, photocatalytic and sonophotocatalytic degradation of MeO in the new reactor and the synergistic effect between sonolysis and photocatalysis were investigated. Effects of operation parameters i.e., US power, TiO2 dosage, liquid circulation velocity and air flow rate on degradation efficiency were investigated and optimized. The results showed that all parameters have optimal values for the sonophotocatalytic degradation of MeO, and the optimum conditions for the new process are US power 600W, TiO2 dosage 3g/L, liquid circulation velocity 4.05×10−2 m/s and air flow rate 0.2L/min. Under the optimum conditions, 91.52% MeO had been degraded within 1h, and the combination of sonolysis and TiO2 photocatalysis exhibited an obvious synergetic effect. [Copyright &y& Elsevier]

Abstract: The Cd TiO2 nanorods were synthesized by the vapor transport method of water molecules, and urea was used as the carbon and nitrogen source. The samples were characterized by X-ray diffraction and photoelectron spectroscopy analysis. The scanning electron microscope images showed that as-prepared TiO2 powders were nanorods, which were formed by the stacking of nanoparticles with a uniform size around 40nm. The degradation of methylene blue with the prepared nanorods demonstrated the photocatalytic activities of TiO2 under visible light are improved by doping with C and N elements. The main reasons were discussed: doping with C and N elements could enhance the corresponding visible-light absorption of TiO2. On the other hand, doping C and N could create more oxygen vacancies in the TiO2 crystals, which could capture the photogenerated electrons more effectively. Thus, more photogenerated holes could be left to improve the photocatalytic activity of TiO2. [Copyright &y& Elsevier]

Antibiotic abuse has led to serious water pollution and severe harm to human health; therefore, there is an urgent need for antibiotic removal from water sources. Adsorption and photodegradation are two ideal water treatment methods because they are cheap, simple to operate, and reusable. Metal organic frameworks (MOFs) are excellent adsorbents and photocatalysts because of their high porosity, adaptability, and good crystal form. The aim of this study is to suggest ways to overcome the limitations of adsorption and photocatalysis treatment methods by reviewing previous applications of MOFs to antibiotic adsorption and photocatalysis. The different factors influencing these processes are also discussed, as well as the various adsorption and photocatalysis mechanisms. This study provides a valuable resource for researchers intending to use MOFs to remove antibiotics from water bodies. [Display omitted] • MOFs exhibit good adsorption and photodegradation efficiency for antibiotics. • Factors to improve their adsorption and photodegradation efficiency are identified. • MOFs recovery can be aided by carriers and magnetic/hydrophobic/nanofiber materials. • The dominant adsorption/photocatalytic degradation mechanisms are summaried. • Future research should focus on applying MOFs to antibiotic removal from water. [ABSTRACT FROM AUTHOR]

Single-component silver phosphate (Ag 3 PO 4) is faced with problems of rapid recombination and poor stability of photo-generated carriers, which severely limits its degradation and practical application of organic pollutants under visible light. In this present paper, we prepared a new type of ZnO/Ag/Ag 3 PO 4 composite photocatalyst with simple precipitation deposition method and photoreduction technology. The structure, crystal form, morphology and light absorption were characterized by XRD, XPS, BET, SEM, TEM, EDS, UV–vis DRS, PL, EIS and transient photocurrent responses. Ciprofloxacin (CIP) was used as the target pollutant to test its photocatalytic activity and stability. The results reveals that the photocatalytic activity of ZnO/Ag/Ag 3 PO 4 composite is significantly enhanced compared with single-component and binary catalysts. After 120 min of visible light irradiation, the degradation of CIP reached 87.1%, and after four cycles, the degradation rate still occupied 75%. The enhanced photocatalytic activity lies in the synergistic effect of ZnO, Ag 3 PO 4 and Ag and the plasmon resonance effect (SPR) on the surface of nano-Ag, which increases the specific surface area of the material, broadens the absorption of visible light, and improves the efficiency of electron-hole pair separation. The capture experiment gives information that the primary active substance is superoxide radical (•O 2 −), and we proposed a possible Z-scheme photocatalytic mechanism. • A novel ZnO/Ag/Ag 3 PO 4 composite was simply synthesized for ciprofloxacin photodegradation. • The composite exhibited superior photocatalytic activity and structure stability ... O 2 − was the main active species during the photodegradation process. • A Z-scheme photodegradation mechanism of CIP over ZnO/Ag/Ag 3 PO 4 was proposed. [ABSTRACT FROM AUTHOR]

• Fe was incorporated into the structure of TiO 2 via one-step thermal process. • Fe-TiO 2 /rGO exhibited excellent activity for BPA and its analogues degradation. • The visible light absorption of Fe-TiO 2 /rGO was extended by Fe ions and rGO. • The photocatalysis was promoted due to the presence of Ti3+. • Superoxide radicals play the prominent role during the photodegradation of BPA. For extending the light response to visible spectrum, an approach to efficient photocatalysts in sustainable energy technology has been a hot research topic. In this work, Fe doped TiO 2 /rGO (Fe-TiO 2 /rGO) was synthesized via one-step hydrothermal deposition method. The presence of Fe-Ti bond and Ti3+ in the photocatalyst was confirmed by XPS, EXAFS and Raman analyses. The batch experiments showed that as-synthesized Fe-TiO 2 /rGO nanocomposites exhibited high photocatalytic performance for bisphenol A (BPA) and its analogues degradation under visible light irradiation (λ ≥ 420 nm). Moreover, Fe-TiO 2 /rGO presented high photocatalytic activity at a high BPA concentration of 95 ppm as well as a wide pH value of 4.5–8.5. Additionally, the extended visible light absorption range Fe-TiO 2 /rGO was demonstrated by low temperature electron spin resonance, UV–vis diffuse reflectance spectra, the transient photocurrent density and electrochemical impedance spectroscopies measurements. The radical quenching and ESR active species trapping experiments implied the main role of superoxide radicals on the high efficient photodegradation of BPA. These findings are crucial for designing TiO 2 -based photocatalysts with high performance for degradation of persistent organic pollutants in wastewater treatment. [ABSTRACT FROM AUTHOR]