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A macroscopic urea-functionalized CdS (CdS-U) is synthesized for the first time. The CdS-U material is formed through the interaction between NH 2 / NH groups on urea and COO − groups on sodium oleate-capped CdS nanoparticles (CdS-So NPs). The CdS-U material exhibites excellent visible light photocatalytic activity and plasticity and has the potential to be produced as rewritable papers. It is convenience to produce a large-scale film by CdS-U. Letters can be written on the CdS-U film and disappear through a dissolution-irradiation process, and then the CdS-U film can be recycled by drying. This novel CdS-U material might be of interest and provide a new chance to advance the application of visible light photocatalyst on rewritable papers. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1D MWO 4 (M = Mn, Co, Cd) nanomaterials were synthesized by electrospinning method. • CoWO 4 nanotubes exhibited superior efficiency in degrading BPA under UV–Vis–NIR light. • The wide-spectrum responses mechanism for MWO 4 (M = Mn, Co, Cd) were explained by DFT. Broadening the absorption region to near-infrared (NIR) light is critical for the photocatalysis due to the larger proportion and stronger penetration of NIR light in solar energy. In the present paper, one-dimensional (1D) MWO 4 (M = Mn, Co, and Cd) materials synthesized by electrospinning technique, were studied by combining the density functional theory (DFT) with experiment results, which possessed the enhanced light absorption capability within the range of 200–2000 nm. It was proved that in the ultraviolet–visible (UV–Vis) region, the absorption bands of CoWO 4 and MnWO 4 samples were attributed to the metal-to-metal charge transfer mechanism, while the absorption of CdWO 4 sample may be referable to the ligand-to-metal charge transfer mechanism. In the near-infrared (NIR) region, the absorption of CoWO 4 and MnWO 4 primarily originated from the d-d orbital transitions of Mn2+ and Co2+. The photocatalytic experimental results showed that the degradation rates for bisphenol A (BPA) over CoWO 4 , MnWO 4 , and CdWO 4 photocatalysts under UV–Vis/NIR light irradiation for 140 min/12 h were 78.8 %/75.9 %, 23.8 %/21.3 %, 12.8 %/8.7 %, respectively. This research offers the novel insights into the precise construction of tungstate catalytic systems and contributes to the advancement of UV–Vis–NIR full spectrum photocatalytic technology, and lays a foundation for a cleaner and more environmental-friendly future. [ABSTRACT FROM AUTHOR]

The modified carbon nitride nanozyme could realize biomimetic catalysis application for evaluation of total antioxidant capacity via self-cascade photocatalytic H 2 O 2 production. [Display omitted] The peroxidase mimics usually requires the addition of exogenous hydrogen peroxide (H 2 O 2), which greatly hinder their practical applications. Herein, through rational co-modification of multiple elements (potassium (K), chlorine (Cl) and iodine (I)), the modified carbon nitride nanomaterials (KCl/KI-CN) could serve as efficient bifunctional catalysts. The multiple elements doping and the incorporation of cyano groups (C N) are deemed to enhance their photocatalytic and peroxidase-like activity, respectively. Based on the photocatalytic function, H 2 O 2 can be produced continuously and steadily via two-electron oxygen reduction over modified carbon nitride under visible light irradiation. Subsequently, the KCl/KI-CN could catalyze the chromogenic substrate by the in-situ produced H 2 O 2. Taking advantage of the bifunctional properties of modified carbon nitride, we for the first time demonstrate a self-cascade catalytic process and apply successfully for the ascorbic acid (AA) detection and versatile total antioxidant capacity (TAC) evaluation. This paper not only prepares an efficiently bifunctional catalyst but also provides a new self-cascade photocatalytic H 2 O 2 production strategy for the peroxidase-like application. [ABSTRACT FROM AUTHOR]

[Display omitted] • Defects were introduced in MIL-125 to narrow the forbidden band width. • Improved the surface acidity of material for efficient degradation of mixed VOCs. • Revealed the catalytic mechanism using in situ DRIFTS spectroscopy and GC–MS. In this paper, the effect of three monocarboxylic acids on MIL-125 synthesis was systematically investigated and the results were discussed in detail. X-ray diffractometry (XRD) and nitrogen adsorption–desorption curves indicated that small molecule acids (acetic acid, propionic acid and butyric acid) affected the morphology of MIL-125 and induced lamellar pores and structural defects in the crystals. Thermogravimetric measurements confirmed the presence of acid-regulated defective metal–organic frameworks (MOFs). Electrochemical tests and density function theory calculations indicated that acid modulation could change the forbidden bandwidth of the material. The acid modification strategy effectively promoted the transfer of photogenerated electrons and enhanced the adsorption and activation of O 2 and H 2 O molecules, generating reactive radicals. The modified MOFs also showed excellent performance in the removal of mixed toluene and chlorobenzene. The degradation pathways of the mixture were analyzed by in situ infrared (IR) and gas chromatography-mass spectrometry (GC–MS). The mixture was converted to chlorophenolic intermediates in the presence of reactive oxygen species, further decomposed to form ethers and ethanol, and finally formed small molecules such as carbon dioxide and water. A feasible method was provided for the preparation of photocatalysts for the treatment of mixed VOCs. [ABSTRACT FROM AUTHOR]

[Display omitted] Owing to the numerous potential applications of ZnO nanomaterials, the development of ZnO-based nanocomposites has become of great scientific interest in various fields. In this paper, we are reporting the fabrication of a series of ZnO/C nanocomposites through a simple "one-pot" calcination method under three different temperatures, 500 ℃, 600 ℃, and 700 ℃, with samples labeled as ZnO/C-500, -600, and -700, respectively. All samples exhibited adsorption capabilities and photon-activated catalytic and antibacterial properties, with the ZnO/C-700 sample showing superior performance among the three. The carbonaceous material in ZnO/C is key to expanding the optical absorption range and improving the charge separation efficiency of ZnO. The remarkable adsorption property of the ZnO/C-700 sample was demonstrated using Congo red dye, and is credited to its good hydrophilicity. It was also found to exhibit the most notable photocatalysis effect due to its high charge transfer efficiency. The hydrophilic ZnO/C-700 sample was also examined for antibacterial effects both in vitro (against Escherichia coli and Staphylococcus aureus) and in vivo (against MSRA-infected rat wound model), and it was observed to exhibit synergistic killing performance under visible-light irradiation. A possible cleaning mechanism is proposed on the basis of our experimental results. Overall, this work presents a facile way of synthesizing ZnO/C nanocomposites with outstanding adsorption, photocatalysis, and antibacterial properties for the efficient treatment of organic and bacterial contaminants in wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] Photocatalysis provides a new way for synchronous H 2 production and organic synthesis at normal temperature and pressure, usually, water and organic substrate function as sources of hydrogen protons and organic products, which are complex and limited by two half-reactions. Employing alcohols as reaction substrates to simultaneously produce H 2 and valuable organics in a redox cycle is worthy studying, to which catalyst design at atomic level holds the key. In this paper, Co elements doped Cu 3 P (CoCuP) quantum dots (QDs) are prepared and coupled with ZnIn 2 S 4 (ZIS) nanosheets to form a 0D/2D p-n nanojunction which can effectively boost aliphatic and aromatic alcohols activation to simultaneously produce H 2 and corresponding ketones (or aldehydes). The optimal CoCuP/ZIS composite demonstrated the highest activity for dehydrogenation of isopropanol to acetone (17.77 mmol⋅g−1⋅h−1) and H 2 (26.8 mmol⋅g−1⋅h−1), which was 2.40 and 1.63 times higher than that of Cu 3 P/ZIS composite, respectively. Mechanistic investigations revealed that such high-performance originated from the accelerated electron transfer of the formed p-n junction and the thermodynamic optimization caused by the Co dopant which was the active site of oxydehydrogenation as a prerequisite step for isopropanol oxidation over the surface of the CoCuP/ZIS composite. Besides that, coupling of the CoCuP QDs can lower the dehydrogenation activation energy of isopropanol to form a key radical intermediate of (CH 3) 2 CHO* for improving the activity of simultaneous production of H 2 and acetone. This strategy provides an overall reaction strategy to obtain two meaningful products (H 2 and ketones (or aldehydes)) and deeply explores the integrated redox reaction of alcohol as substrate for high solar-chemical energy conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Copper indium sulfide QDs are emerging as versatile visible-light photocatalysts. • Different synthesis methods determine the properties and performances. • Modification strategies such as heterojunction formation improve the activity. • Excellent results in photocatalytic degradation, H 2 production and CO 2 reduction. • Promising prospects for future development and wider applications. Since the advent of photocatalytic technology, scientists have been searching for semiconductor materials with high efficiency in solar energy utilization and conversion to chemical energy. Recently, the development of quantum dot (QD) photocatalysts has attracted much attention because of their unique characteristics: small size, quantum effects, strong surface activity, and wide photoresponse range. Among ternary chalcogenide semiconductors, CuInS 2 QDs are increasingly examined in the field of photocatalysis due to their high absorption coefficients, good matching of the absorption range with sunlight spectrum, long lifetimes of photogenerated electron-hole pairs and environmental sustainability. In this review paper, the structural and electronic properties, synthesis methods and various photocatalytic applications of CuInS 2 QDs are systematically expounded. The current research status on the photocatalytic properties of materials based on CuInS 2 QD is discussed combined with the existing modification approaches for the enhancement of their performances. Future challenges and new development opportunities of CuInS 2 QDs in the field of photocatalysis are then prospected. [ABSTRACT FROM AUTHOR]

[Display omitted] As a renewable green energy, hydrogen has received widespread attention due to its huge potential in solving energy shortages and environment pollution. In this paper, a one-step solvothermal method was applied to grow ultra-thin g-C 3 N 4 (UCN) nanosheets and NiS nanoparticles on the surface of ZnIn 2 S 4 (ZIS). A ternary NiS/ZnIn 2 S 4 /ultra-thin-g-C 3 N 4 composite material with dual high-speed charge transfer channels was constructed for the advancement of the photocatalytic H 2 generation. The optimal ternary catalyst 1.5wt.%NiS/ZnIn 2 S 4 /ultra-thin-g-C 3 N 4 (NiS/ZIS/UCN) achieved a H 2 evolution yield reached to 5.02 mmolg−1h−1, which was 5.23 times superior than that of pristine ZnIn 2 S 4 (0.96 mmolg−1h−1) and even outperform than that of the best precious metal modified 3.0 wt%Pt/ZnIn 2 S 4 (4.08 mmolg−1h−1). The AQY at 420 nm could be achieved as high as 30.5%. The increased photocatalytic performance of NiS/ZIS/UCN could be ascribed to the type-I heterojunctions between intimated ZIS and UCN. In addition, NiS co-catalyst with large quantity of H 2 evolution sites, could result in efficient photo-induced charges separation and migration. Furthermore, the NiS/ZIS/UCN composite exhibited excellent H 2 evolution stability and recyclability. This work would also offer a reference for the design and synthesis of ternary co-catalyst with heterojunction composite for green energy conversion. [ABSTRACT FROM AUTHOR]

The efficient photocatalytic degradation of o-phenylphenol over Z-scheme Bi 4 O 5 I 2 /BiOBr hybrid accelerated by I 3 −/I− and Bi5+/Bi3+ redox mediators. [Display omitted] • Z-scheme Bi 4 O 5 I 2 /BiOBr hybrids with 3D/2D spatial structure were fabricated. • The hybrids show efficient photocatalytic activity toward phenolic contaminants. • The OPP degradation rate over the Bi 4 O 5 I 2 /BiOBr-5 was 3.43 times higher than that of Bi 4 O 5 I 2. • A Z-scheme mechanism guided by I 3 −/I− and Bi5+/Bi3+ redox mediators was proposed. Z-scheme photocatalysts commonly possess both high charge separation efficiency and strong redox ability. In this paper, novel 3-dimensional/2-dimensional (3D/2D) structured bismuth-rich bismuth oxide iodide/bismuth oxide bromide (Bi 4 O 5 I 2 /BiOBr) hybrids with Z-scheme heterojunctions were first prepared. The in situ generated I 3 −/I− and Bi5+/Bi3+ redox mediators in Bi 4 O 5 I 2 /BiOBr hybrids greatly improve their photocatalytic activity toward phenolic contaminants. Their structure, morphology, optical properties, and electrochemical properties were characterized. Scanning electron microscopy images demonstrated that the 2D BiOBr nanoplates were evenly and tightly anchored on the surface of the 3D Bi 4 O 5 I 2 microspheres. This novel 3D/2D spatial structure was beneficial for the formation of heterojunctions between BiOBr and Bi 4 O 5 I 2 , which improved the quantum efficiency through interfacial charge transfer. The Bi 4 O 5 I 2 /BiOBr hybrids exhibited excellent photocatalytic activities toward o-phenylphenol (OPP), p- tert -butylphenol, 4-chlorophenol, and p-nitrophenol. Bi 4 O 5 I 2 /BiOBr-5 possessed the best activity in decomposing OPP, which was approximately 3.43 times higher than that of pure Bi 4 O 5 I 2. The well-matched energy bands of components in the hybrids facilitated the interfacial charge separation through an effective Z-scheme transfer direction guided by I 3 −/I− and Bi5+/Bi3+ redox mediators. Based on the results of electron spin paramagnetic resonance and trapping experiments, a mechanism was proposed for the degradation of pollutants using the Bi 4 O 5 I 2 /BiOBr hybrids. [ABSTRACT FROM AUTHOR]

[Display omitted] Semiconductor photocatalysis, as a means of utilizing stranded renewable solar resources, is now emerging as a viable and promising approach for increasingly severe water pollution. In this work, a high-performance photocatalytic system has been fabricated by immobilizing spiky TiO 2 /Au nanohybrids on one side of hydrophobic nanoPE substrate (PE-TiO 2 /Au) that forces the enabling of air–liquid–solid triphase photocatalytic interface. Such a triphase system allows efficient oxygen access to the photocatalyst surface, which is feasible for charge separation and reactive oxygen species (ROS) production. Two modes of triphase systems with different gas flow paths were constructed, in which PE-TiO 2 /Au was floating on the aqueous solution surface (exposed mode) or immersing in aqueous phase (immersed mode). It is worth mentioning that the exposed PE-TiO 2 /Au enables a more efficient oxygen supply, thus leading to a 5.5-fold and 1.8-fold higher reaction kinetics as compared to normal liquid–solid diphase system and immersed PE-TiO 2 /Au. Meanwhile, PE-TiO 2 /Au also exerts bactericidal effect under visible light irradiation, which effectively inactivates S.aureus (>99.9%) in a lean period of 30 min. The qualities of high lethality rate and short reaction time are endowed to PE-TiO 2 /Au due to the co-effect of unique triphase interface microenvironment and elaborate heterojunction of spiky TiO 2 /Au nanohybrids. In this paper, we have revealed for the first time that the antibacterial efficiency can be effectively improved by increasing the oxygen supply with the construction of three-phase interface, which represents a promising option in designing highly efficient photocatalytic systems for sewage purification applications. [ABSTRACT FROM AUTHOR]

Construction of Schottky junctions based DUT-67 and Pd nanosheet with enhanced charge carrier separation efficiency for efficient photoreduction of CO 2. [Display omitted] • DUT-67 decorated with Pd nanosheet was prepared. • 0.3-Pd/DUT-67 had considerable photocatalytic CO 2 reduction to CO efficiency of 48.6 μmol g−1. • Schottky barrier at Pd/DUT-67 interface boosts separation of electron-hole pairs. The separation, transfer and recombination of charge often affect the rate of photocatalytic reduction of CO 2. Schottky junctions can promote the rapid separation of space charge. Therefore, in this paper, Pd nanosheets were grown on the surface of DUT-67 by a hydrothermal method, and a Schottky junction was constructed between DUT-67 and Pd. Under the action of the Schottky junction, the CO yield of 0.3-Pd/DUT-67 reached 12.15 μmol/g/h, which was 17 times higher than that of DUT-67. Efficient charge transfer was demonstrated in photochemical experiments. The large specific surface area and the increased light utilization rate also contributed to the increase in the CO 2 reduction efficiency. In addition, the mechanism of Pd/DUT-67 photocatalytic reduction of CO 2 was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • S, P co-doped porous carbon nitride microtube (SPCN) was synthesized by using melamine and ammonium dihydrogen phosphate as precursors. • Ammonium dihydrogen phosphate can not only control the morphology of carbon nitride from nanorods to porous microtube, but also provide a potential P source for P-doped CN. • The prepared SPCN0.1 showed the highest photocatalytic hydrogen evolution rate of 4200.3 µmol g-1h−1 and the apparent quantum efficiency of HER reached up to 10.3 % at 420 nm. • The enhanced photocatalytic performance may be attributed to the synergistic effect of S, P doping and morphology structure of carbon nitride. Hetero-atoms doping or morphology controlling of carbon nitride (g-C 3 N 4) can availably regulate its electronic band structure and optimize photocatalytic performance under visible light. Herein, sulful (S), phosphorus (P) co-doped porous carbon nitride microtubes (SPCN) was synthesized by using ammonium dihydrogen phosphate and melamine as precursors, in which ammonium dihydrogen phosphate can not only control the morphology of carbon nitride from nanorods to porous microtubes, but also provide a potential P source for P-doped CN. The prepared SPCN0.1 with the content of 0.1 g ammonium dihydrogen phosphate displayed the highest photocatalytic hydrogen generation rate of 4200.3 µmol g-1h−1, which was approximately 25 and 1.6 folds by bulk g-C 3 N 4 (CN) and sulphur doped g-C 3 N 4 microrods (SCN), respectively. Moreover, the apparent quantum efficiency of HER reached up to 10.3 % at 420 nm. The enhanced photocatalytic performance may be attributed to the synergistic effect of S, P doping and morphology structure of carbon nitride, which effectively accelerated the separation and transfer of photogenerated electron-hole pairs, proved by photoluminescence spectra, time-resolved PL spectra, electrochemical impedance spectrum and transient photocurrent responses. The novel synthetic method described in this paper is an effective approach to regulate the morphology of g-C 3 N 4 via non-metal doping with superior photocatalytic performance. [ABSTRACT FROM AUTHOR]

By taking advantage of in-situ generated H 2 O 2 , Z-scheme Fe 2 (MoO 4) 3 /Ag/Ag 3 PO 4 heterojunction displayed outstanding degradation performance. [Display omitted] • Internal-electric-field is built at interface, resulting in a Z-scheme routine of e - • k of Fe 2 (MoO 4) 3 /Ag/Ag 3 PO 4 is 254 and 7.0 times than those of Fe 2 (MoO 4) 3 and Ag 3 PO 4. • H 2 O 2 is activated on Fe 2 (MoO 4) 3 for •OH, avoiding quenching effect on h + and e - • k is improved by 1.7 times via turning waste (H 2 O 2) into wealth (•OH) • 91.2% of removal efficiency is remained after 5 runs, while that of Ag 3 PO 4 is 68.1% Ag 3 PO 4 -based photocatalysts have been deeply studied in environmental remediation; however, two problems limited their further application: photocorrosion and quenching effect by in-situ generated H 2 O 2. To addressed these two questions simultaneously, Fe 2 (MoO 4) 3 was coupled with Ag 3 PO 4 to construct Z-scheme Fe 2 (MoO 4) 3 /Ag/Ag 3 PO 4 heterojunction driven by internal-electric-field. The rhodamine B degradation rate of heterojunction was 254 and 7.0 times higher than those of Fe 2 (MoO 4) 3 and Ag 3 PO 4 , respectively. The outstanding photoactivity was due to the high visible-light harvest, low interface resistance, high separation efficiency of charge carriers, long lifetime of hole (h +) and electron (e -), well-preserved oxidation potential of h +, and especially photocatalytic produced H 2 O 2 inside the system. The in-situ generated H 2 O 2 was fully activated to be •OH on the Fe 2 (MoO 4) 3 surface via a Fenton reaction, leading to the elimination of quenching effect on h + and e -, and generation of more •OH. Additionally, in Z-scheme heterojunction, e - transferred from Ag 3 PO 4 to Fe 2 (MoO 4) 3 , avoiding the accumulation on Ag 3 PO 4 surface, and hence suppressing the photocorrosion. As a result, 91.2% of degradation efficiency remained after 5 cycles. This paper provides a new method to simultaneously increase the degradation rate by utilizing the in-situ generated H 2 O 2 and improve the stability of Ag 3 PO 4 via constructing a Z-scheme heterojunction. [ABSTRACT FROM AUTHOR]

• The Fe 3 O 4 and MoS 2 were firmly heterotopic connected by simple reaction. • Micro-nano heterogeneous structures were constructed on the sponge skeletons. • Endowing the PU-based sponges with both superhydrophobicity and photocatalysis. • Simultaneous oil/water separation and dyes degradation under light source. • Continuous oil/water separation kinetics and physical mechanism were analyzed. The diffusion of stubborn oils and organic pigments has become a severe environmental pollution problem. Promisingly, the combination of superhydrophobicity and photocatalysis is expected to provide an efficient, economical and simple solution. In this paper, a kind of superhydrophobic and super-lipophilicity polyurethane (PU)-based sponge was reported by a strategy of undergoing ferric tetroxide loading (Fe 3 O 4 @PU), polydopamine fixation (PDA-Fe 3 O 4 @PU), octadecylamine grafting (ODA-Fe 3 O 4 @PU) and molybdenum disulfide loading (MoS 2 -ODA-Fe 3 O 4 @PU) successively. The results show that the MoS 2 -ODA-Fe 3 O 4 @PU sponge exhibits outstanding superhydrophobicity (with maximum water contact angle of 161.64°), excellent oil absorption capacity (60–109 wt/wt), robust stability in extreme environments and great oil/water separation ability. In addition, the MoS 2 -loaded sponge demonstrates desirable outcomes in decomposing methyl orange and methylene blue under light source, and a dual-functional purification system with a heterogeneous polyurethane-based sponge (the upper part is MoS 2 -ODA-Fe 3 O 4 @PU and the bottom part is MoS 2 @PU) endowed with superhydrophobicity and photocatalysis can purify water by separating oils and decomposing methylene blue simultaneously. [ABSTRACT FROM AUTHOR]

• Design and preparation of Au decorated CeO 2 /ZnO hybrid composite. • The synergic effect of type-II heterojunction, SPR effect and oxygen vacancy. • Superior photocatalysis activity for Rhodamine B, 4-nitrophenol and Naproxen. In this paper, the urchin-like CeO 2 /ZnO@Au photocatalyst was rationally designed and prepared through hydrothermal method, chemical precipitation and photo reduction deposition. The optimal photocatalyst (CZA8) degraded Rhodamine B (RhB), 4-nitrophenol (4-NP) and Naproxen (NPX) about 100% within 20 min, 91.4% within 60 min and 88.9% within 30 min under Xe lamp illumination, respectively. Besides, the CZA8 possesses outstanding photo corrosion resistance capacity which has been verified with the cycle degradation experiments. The photocatalyst displays excellent light response and efficient separation of photo-induced carriers due to the fabrication of type-II heterojunction, the presence of surface plasmon resonance (SPR) effect and as well as the oxygen vacancy. The oxygen vacancy was systematically characterized by XPS, PL and Raman. Moreover, the photocatalytic degradation pathways are proposed based on the LC-MS results. Finally, a novel photocatalytic mechanism for photocatalytic oxidation of RhB, 4-NP and NPX is discussed and schematically illuminated. [ABSTRACT FROM AUTHOR]

• A novel NS-CN/FeOCl system was synthesized via the calcination-hydrothermal method. • The prepared samples were employed for nitrogen fixation under mild condition. • The NS-CN/FeOCl(20%) exhibits 3.4 times higher than the CN in the ammonia production. • The mechanism of N 2 fixation was illustrated for a better understanding of the photoactivity. Climate change, global warming, and population growth have led researchers to use eco-sociable procedures for the N 2 reduction reaction. It has discovered that N 2 molecule can be transformed into NH 3 in ambient circumstances with nanocomposites upon visible irradiation. In this research paper, a new visible-light-driven photocatalyst was constructed, with various weight percents of FeOCl particles (10, 20, 30, and 40%) that have adhered on NS-CN. Subsequently, multiple features of the nanocomposites were assayed in detail. The results illustrated that the NS-CN/FeOCl (20%) system has remarkable photoactivity in the NH 4 + production reaction in comparison with the NS-CN and CN, which showed 2.5 and 8.6 higher activity, respectively. The durability of NS-CN/FeOCl (20%) system, as a substantial factor, was assayed for 5 recycles. Moreover, the effect of electron quenchers, pH of media, and solvent was studied. At last, a feasible Z-scheme mechanism for the remarkable improvement of N 2 fixation efficiency was offered. [ABSTRACT FROM AUTHOR]

• Plasmonic Pt-Au/BiVO 4 single-crystal photocatalyst was constructed. • It was synthesized using crystal-facet engineering and selective photodeposition. • The unique photocatalyst can promote consecutive separation of photocarriers. • They are resulted from orientation transfer of BiVO 4 , Z-scheme Au/BiVO 4 , and Au-Pt. Constructing Z-scheme photocatalysts is one of the most effective technologies to enhance the photocatalytic reduction or oxidation ability in artificial photosynthesis. For the BiVO 4 photocatalyst, it usually shows limited photocatalytic ability because of the severe bulk recombination of photogenerated carriers and the poor reduction reaction of photogenerated electrons. In this paper, a novel plasmonic Z-scheme Pt-Au/BiVO 4 single-crystal photocatalyst was constructed to solve the above issues. Here, Au nanoparticles are selectively deposited on the electron-rich (0 1 0) facet of BiVO 4 , while Pt nanoparticles are selectively modified on the Au surface. Photocatalytic results indicated that the resultant Pt-Au/BiVO 4 Z-scheme photocatalyst exhibits an obviously higher photocatalytic performance than pure BiVO 4 , Au/BiVO 4 , randomly deposited BiVO 4 (Pt-Au/BiVO 4 (R)) and conventional Pt-Au/BiVO 4. More importantly, compared with the well-known Pt/BiVO 4 (2.0 wt%), the Pt-Au/BiVO 4 not only exhibits a higher photocatalytic performance, but also loads a lower amount of high-cost Pt cocatalyst. The excellent photocatalytic activity of the plasmonic Z-scheme Pt-Au/BiVO 4 photocatalyst can be attributed to the synergistic effect of crystal-facet engineering and selective loading of Pt-Au, which results in the orientation transfer of photogenerated carriers in the single-crystal BiVO 4 , the enhanced reduction power of photogenerated electrons, and the rapid oxygen-reduction reaction on Pt cocatalyst. [ABSTRACT FROM AUTHOR]

• TBAOH assisted synthesis of ultrathin BiOCl-T nanosheets with exposed (1 1 0) face. • Deionized water was used as the solvent for the preparation of BiOCl-T. • BiOCl-T exhibited enhanced charge separation efficiency. • BiOCl-T displayed superior photocatalytic activity in CBZ degradation. • h+, O 2 −, and OH predominated the photocatalytic degradation process of CBZ. Ultrathin nanosheets show great promise in photocatalytic technology, due to short path for electron transfer and large surface for reactant adsorption. However, there is no report that ultrathin nanosheets photocatalyst has been used to degrade carbamazepine (CBZ) in aquatic environment. This paper aimed at fabricating ultrathin BiOCl nanosheets to improve the photocatalytic degradation efficiency of CBZ. Herein, tetrabutylammonium hydroxide (TBAOH) was firstly applied to synthesize ultrathin BiOCl nanosheets (BiOCl-T) by a simple hydrolysis route in water at ambient conditions. TBAOH could act as a structure-directing agent, determining the structure and property of BiOCl-T. Assisted by TBAOH, BiOCl-T exhibited ultrathin nanosheets structure with preferential exposed (1 1 0) face. PL, photocurrent density, and EIS Nyquist plots demonstrated the enhanced charge separation efficiency in BiOCl-T. Furthermore, BiOCl-T displayed large pore size and specific surface area. Thus, BiOCl-T showed high photocatalytic activity toward CBZ degradation under simulated sunlight. Upon 30 min irradiation, the degradation efficiency of CBZ was 91.1% with fast degradation kinetics, which is 2.46 times higher than ordinary BiOCl. Active species of h +, O 2 −, and OH contributed to CBZ degradation reaction. The obtained result provides a novel viewpoint to fabricate ultrathin nanosheets and broadening their application in the degradation of recalcitrant pharmaceuticals. [ABSTRACT FROM AUTHOR]

• 3-D Ag/ZnO@CF photocatalysts with enhanced mass transfer were fabricated. • Hierarchical structure and loaded cocatalysts improved the photocarriers separation. • Phenol-Cr (VI) ester contributed to the homogeneous self-elimination of pollutants. • Synergistic removal of phenol and Cr(VI) by hetero- and homogeneous photocatalysis. Synergistic photocatalysis offers great potential for simultaneously treating organic and heavy metal pollutants. Although considerable progress has been made, this technology is seriously restricted by the poor photoactivity of heterogeneous catalysts, and the contribution from homogeneous intermoleculars has been overlooked. In this paper, the Ag/ZnO@CF with 3-D hierarchical porous structure was fabricated and used to synergistically remove phenol and Cr(VI) from water. Due to the enhanced mass transfer and cocatalysts-facilitated charge separation, 3-D photocatalysts exhibited significantly improved activity for heterogeneous photocatalysis. Furthermore, both experimental characterizations and DFT calculations evidenced the formation of phenol-chromate(VI) esters with ligand-to-metal charge transfer from benzene ring to central chromium ion under photoexcitation. Thereafter, the effects of heterogeneous and homogeneous photocatalysis on the treatment efficiency of multiplex pollutants were investigated. In an ideal scenario, 2.4 and 2.3 times higher phenol and Cr(VI) removal rate were achieved compared to single catalytic reactions. This work not only offers new material strategy for photocatalyst exploration, but also provides new insights into the multiphase homogeneous catalysis contributed by intermolecular interactions. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract A composite photocatalyst, sliver/graphitic carbon nitride/pre-treated carbon fiber paper (Ag/g-C 3 N 4 /t-CFP), has been innovatively designed and successfully fabricated by loading Ag and g-C 3 N 4 species on t-CFP using the combined methods of thermal polymerization and improved electroless plating (IEP) through ultrasonic spray atomization (USA). A micro-droplet system, USA is able to eliminate the adverse influence of concentration gradient effectively. The samples obtained were carefully characterized in terms of morphology, phase, chemical structure, and optical performance. Results suggested that compared with the conventional electroless plating (CEP), IEP strategy could ensure a better dispersibility and smaller size of Ag nanoparticles. Accordingly, the IEP-prepared Ag/g-C 3 N 4 photocatalyst on t-CFP (ACNT-iep) exhibited a pseudo-first-order kinetics constant 12 times higher than that of the neat g-C 3 N 4 on t-CFP for methylene blue (MB) degradation. Photoluminescence (PL) and electrochemical impedance spectra (EIS) demonstrated a more efficient separation of photogenerated carriers in ACNT-iep at the same time. The photocatalytic activity of ACNT-iep could be maintained at a high level over five cycles. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Bi 2 O 2 CO 3 -based ternary composite materials are generally synthesized by two- or multi-step method and special precursor of CO 3 2− is usually utilized in synthesis of Bi 2 O 2 CO 3 , which are time-consuming, laborious and relatively costly. In this paper, for the first time, a facile one-step solvothermal method is used to fabricate Z-scheme Bi 2 O 2 CO 3 /Bi/Bi 2 WO 6 ternary composites. Interestingly, ethylene glycol not only acts as solvent for the reaction system, but also reduced Bi3+ into metallic Bi and itself is oxidized to CO 3 2−, which could construct Bi 2 O 2 CO 3. On this occasion, Bi 2 O 2 CO 3 /Bi/Bi 2 WO 6 ternary composites are obtained after one-step method. High resolution transmission electron microscopy clearly reveals each component in composites. The as-prepared samples could be applied in various photocatalytic activities. Under solar light irradiation, Bi 2 O 2 CO 3 /Bi/Bi 2 WO 6 composites exhibited prominent photodegradation performances for both ciprofloxacin and bisphenol A. Meanwhile, these composites could also be used in efficient photoreduction of CO 2. The efficient photocatalytic activity could be mainly ascribed to Z-scheme electron transfer mechanism in ternary composites, which is determined by surface redox reactions, active species trapping experiment, electron spin resonance spectrum. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract This paper is designed for elevating the photocatalytic H 2 -evoultion performance of g-C 3 N 4 through the modification of AgNbO 3 nanocubes. Via the microwave heating method, g-C 3 N 4 was in-situ formed on AgNbO 3 surface to fabricate a close contact between the two semiconductors in forty minutes. X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), X-ray photoelectron spectroscopy (XPS) experiments were performed to confirm the binary structure of the synthesized AgNbO 3 /g-C 3 N 4 composite. N 2 -adsorption and visible diffuse reflection spectroscopy (DRS) analyses indicated that the addition of AgNbO 3 to g-C 3 N 4 showed nearly negligible influence on the specific surface area and the optical property. Photoluminescence (PL) spectroscopy experiment suggested that the AgNbO 3 /g-C 3 N 4 displayed reduced PL emission and longer lifetime of photoexcited charge carriers than g-C 3 N 4 , which could be ascribed to the suitable band potential and the intimate contact of g-C 3 N 4 and AgNbO 3. This result was also confirmed by the transient photocurrent response experiment. The influence of the enhanced charge separation was displayed in their photocatalytic reaction. AgNbO 3 /g-C 3 N 4 sample showed enhanced performance in photocatalytic H 2 -generation under visible light illumination. The H 2 -evolution rate is determined to be 88 μmol·g−1·h−1, which reaches 2.0 times of g-C 3 N 4. This study provides a feasible and rapid approach to fabricate g-C 3 N 4 based composite. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Photocatalytic reduction can be an effective and promising technology for the selective reduction of aromatic nitro organics. In this paper, a novel Z-scheme CdS/SnS 2 photocatalyst was well-designed and fabricated via simple in-site reaction process containing thioacetamide as a sulfur sources and cubic CdSnO 3 as template. The resulting CdS/SnS 2 composite has well-constructed cubic nanostructure of strong adhesion between CdS and SnS 2 , presenting high absorption to visible light. Importantly, strong charge transfer between the contacting regions of CdS and SnS 2 through the intermediate sulfur atoms combined with both metals was generated, which speeds up separation of photogenerated electron and hole. The advantageous combination of high light-harvesting and effective charge transfer is responsible for the excellent photocatalytic activity at the CdS/SnS 2 heterointerface. Resultantly, the prepared CdS/SnS 2 composites exhibit high conversion efficiency and selectivity on 4-nitroaniline (4-NA) reduction in the aqueous solution containing ammonium formate under visible light irradiation, which can reduce almost all 4-NA within 12 min. Trapping experiments and ESR analysis demonstrated that ammonium formate not only can effectively decrease recombination of photogenerated charge carriers but also react with holes to generate CO 2 − radicals possessing strong reduction ability. The 4-NA are effectively photo-reduced by the synergistic effect of electrons and CO 2 − radicals. According to the experimental results, a possible Z-scheme charge transfer mechanism was proposed. Besides, the photo-reduction of aromatic nitro organics possessed different para-groups (p-nitrophenol, nitrobenzene, and p-nitrobenzaldehyde) was also investigated. It is found that the electron-drawing group can decrease the electron density of its para-position nitryl, which quickens the nitro reduction. [ABSTRACT FROM AUTHOR]

Graphical abstract Schematic of the band-gap structures of BiOF/BiOI and the possible charge separation processes. Abstract This is the first paper to report a series of bismuth oxyfluoride/bismuth oxyiodide (BiO p F q /BiO x I y) nanocomposites with different F/I molar ratios, pH values, and reaction temperatures that were synthesized through a template-free and controlled hydrothermal method. These nanocomposites were characterized through scanning electron microscope energy dispersive microscopy (SEM-EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), and diffuse reflectance spectroscopy (DRS). Under visible-light irradiation, the BiO p F q /BiO x I y composites exhibited excellent photocatalytic activities in the degradation of crystal violet (CV) and 2-hydroxybenzoic acid (HBA). The order of rate constants was BiOF/BiOI > BiOI ≫ BiOF. The photocatalytic activity of BiOF/BiOI composites reached a maximum rate constant of 0.2305 h−1, 1.2 times higher than that of BiOI and 100 times higher than that of BiOF. Thus, the derived BiOF/BiOI is crucial for photocatalytic activity enhancement. After the removal of CV in the third cycle, no apparent deficits in photocatalytic activity were observed, and the observed deficit was 8.2% during the fifth run. Overall, the catalytic activity and stability observed for the proposed composites were determined to be adequate under visible-light irradiation. For various scavengers, the noted quenching effects demonstrated that reactive O 2 − has a notable role in the degradation of the applied CV. [ABSTRACT FROM AUTHOR]

This paper presents an unprecedented systematic synthetic study of a controlled hydrothermal method for the preparation of bismuth oxychloride/bismuth oxybromide/bismuth oxyiodide ternary composites (BiO x Cl y /BiO m Br n /BiO p I q ). The pH, temperature, and KCl:KBr:KI molar ratio for the reactions were adjusted to control the compositions and morphologies of BiO x Cl y /BiO m Br n /BiO p I q composites. Scanning electron microscopy-energy dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, ultraviolet–visible diffuse reflectance spectroscopy, Brunauer–Emmett–Teller specific surface areas, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy, and electron paramagnetic resonance spectroscopy were applied to the products. The photocatalytic activities of dispersions were examined by monitoring the 2-hydroxybenzoic acid (HBA) and crystal violet concentrations. Various scavengers demonstrated quenching effects. O 2 − was crucial to HBA degradation, whereas h + and OH played minor roles in HBA degradation. This text hypothesizes possible photodegradation mechanisms. [ABSTRACT FROM AUTHOR]

The intriguing features of two-dimensional (2D) materials such as better charge carrier separation and abundant surface reaction sites endow them with potential applications as cocatalysts in photocatalysis. In this paper, a ternary 2D nickel hydroxide/sulfides nanosheet composed of Ni(OH) 2 , Ni 3 S 2 and Ni x S 6 was loaded on CdS nanospheres by a simple chemical deposition route. The composition of nickel hydroxide/sulfides was determined clearly through an overall analysis using X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. Mott-Schottky, electrochemical impedance, steady-state and time-resolved photoluminescence spectroscopy were used to investigate the charge transfer process in CdS and Ni(OH) 2 /Ni 3 S 2 /Ni x S 6 -CdS. The results confirm that a synergistic effect of Ni(OH) 2 /Ni 3 S 2 /Ni x S 6 on CdS has occurred under light irradiation, where the Ni(OH) 2 and nickel sulfides act as hole storage and surface reaction sites, respectively, to promote the charge transfer on CdS. The improved charge transfer and separation efficiency as well as the increased surface reaction sites in Ni(OH) 2 /Ni 3 S 2 /Ni x S 6 -CdS finally result in a dramatically improved photocatalytic performance. The photocatalytic H 2 evolution rate of Ni(OH) 2 /Ni 3 S 2 /Ni x S 6 -CdS is ca . 46 times higher than that of CdS, and the photocatalytic stability of CdS is also improved substantially under visible light irradiation. [ABSTRACT FROM AUTHOR]

Two hierarchical ZnO micro/nano-materials have been prepared by a short-time (45 min) hydrothermal reaction without any surfactants. The different morphologies have been characterized comprehensively by XRD, SEM, TEM and XPS technologies. The hierarchical micro- and nano-structures are respectively consisted by the subordinate nano-pieces and nano-hexagonal-rods. Under the illumination of the simulated solar light, the nano-piece-aggregate spends 40 min to degrade the 98% of rhodamine 6G solution (10 −5 mol/L), whereas the nano-rod-aggregate only degrades the 78% of the solution in the same condition. Moreover, the photocatalytic performances of the two ZnO aggregates are significantly improved by loading with Au nanoparticles (NPs) in the same assembly process. The nano-piece-aggregate decorated with the Au NPs spends 24 min to decompose the rhodamine 6G solution completely, while nano-rod-aggregate decorated with the Au NPs needs 28 min. The related photocatalytic mechanisms are proposed in this paper. [ABSTRACT FROM AUTHOR]

The solid-state Z-scheme trinary/binary heterostructures show the advantage of utilizing the high-energy photogenerated charge carriers in photocatalysis. However, the key factors controlling such Z-scheme in the binary heterostructures are still unclear. In this paper, we showed that oxygen vacancies could act as an interface electron transfer mediator to promote the direct Z-scheme charge transfer process in binary semiconductor heterostructures of CdS/ZnS. Increasing the concentration of surface oxygen vacancies of ZnO crystal can greatly enhance photocatalytic hydrogen generation of CdS/ZnO heterostructure. This was attributed to the strengthened direct Z-scheme charge transfer process in CdS/ZnO, as evidenced by steady-state/time-resolved photoluminescence spectroscopy and selective photodeposition of metal particles on the heterostructure. [ABSTRACT FROM AUTHOR]

A novel solar responsive photocatalytic fuel cell (PFC) consisted of a WO 3 /FTO photoanode and an air-breathing cathode was successfully prepared for simultaneous pollutant degradation and power production. The as-prepared PFC system exhibited outstanding photocurrent performances, which were attributed to the combined effects of the large specific surface area and the improved oxygen transportation by air-breathing cathode design, as well as the enhanced light absorption by transparent FTO substrate. Oxytetracycline hydrochloride was used as the model compound in this paper, and parametric effects on the PFC performances were deeply investigated. Results showed that increasing electrolyte concentration and light density were effective approaches to enhance power outputs. In terms of oxytetracycline hydrochloride concentration, the maximum power density firstly enhanced when oxytetracycline hydrochloride concentration increased to 0.5 mmol/L, then dropped dramatically with further increasing of oxytetracycline hydrochloride concentration to 2.0 mmol/L. The highest short-circuit current density of 372.4 μA/cm 2 and maximum power density of 36.3 μW/cm 2 were obtained when the PFC operated at the optimum operation condition of 0.1 mol/l Na 2 SO 4 electrolyte, 200 mW/cm 2 light density and 0.5 mmol/L oxytetracycline hydrochloride. The PFC-assisted photocatalytic degradation experiments also suggested a promising application of the as-prepared PFC system in refractory wastewater treatment. [ABSTRACT FROM AUTHOR]

In this paper, CeO 2 microplates were synthesized by a sol-gel auto-combustion method. AgI nanoparticles (NPs) were then deposited onto the surface of CeO 2 via a facile deposition–precipitation method. The as-prepared AgI/CeO 2 samples were characterized by various analytical techniques. The composites exhibited superior photocatalytic activities for the organic dyes (RhB) and the refractory pollutant (tetracycline (TC), a typical antibiotic) degradation under visible light irradiation. The CA-19.03 sample exhibited the highest photocatalytic activity. The enhanced photocatalytic performance could be ascribed to the improved separation of photogenerated charge carriers due to well-matched band structure. [ABSTRACT FROM AUTHOR]

This study provides the first attempt to combine UiO-66(Zr) with Bi 2 MoO 6 for the preparation of composite via electrostatic interaction induced self-assembly process. Synthesized products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscope (FT-IR), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface area analyse and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). The photocatalytic activities of as-obtained Bi 2 MoO 6 /UiO-66(Zr) composites were assessed by degradation of Rhodamine B (Rh B) under the visible-light irradiation. Comparing to the pristine materials, the developed Bi 2 MoO 6 /UiO-66(Zr) composite with Bi:Zr molar ratio 2:1, labelled as BMUO-2, showed the best photocatalytic activity. It was supposed that the participation of Bi 2 MoO 6 increased the use of solar energy and the existence of UiO-66(Zr) restrained the recombination rate of photo-generated electron-hole pairs. Moreover, Bi 2 MoO 6 /UiO-66(Zr) composite showed excellent stability and recyclability during cycling experiment. The mechanism and plausible pathway of Rh B degradation were also discussed in this paper. [ABSTRACT FROM AUTHOR]

In this paper, a series of BiOI/ZnO photocatalysts containing various BiOI contents were prepared by a facile two-step synthetic method. The structure and crystal phase, morphology, surface element analysis, optical property of as-prepared samples are measured by X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV–Vis diffuse reflectance spectrometry (DRS). BiOI/ZnO photocatalytic activities of the prepared photocatalysts were evaluated by photocatalytic degradation of phenol under simulated light irradiation. The phenol degradation rate reached 99.9% within 2 h under simulated solar light irradiation. The probable photocatalytic mechanism of composites photocatalysts is discussed by active species trapping experiments, the surface photovoltage (SPV), the transient photovoltage (TPV) and photoluminescence (PL) measurements. The results manifest that the superior photocatalytic activity of BiOI/ZnO composites is derived from the strong internal electric field between BiOI and ZnO, which is beneficial for the effective separation and transfer of photogenerated charges in ZnO. Moreover, the loading of BiOI on the surface of ZnO inhibited the recombination of photogenerated charge carriers in ZnO, resulting in excellent photocatalytic activity. On the contrary, the effect of an extension of the light absorption range induced by the introduction of BiOI on the phenol degradation activity is not significant. [ABSTRACT FROM AUTHOR]

Recently, the photocatalytic applications of silver chloride have been paid closed attention for the excellent ability to photodegrade organic pollutants. Comparing with other catalysts, the silver chloride presents outstanding photocatalytic activity. However, it also suffers from the poor photocatalytic stability. This very paper is focusing on the one-step wet chemical process of preparing Ag/AgCl/GO photocatalyst with high photocatalytic activity and stability. The detailed characterizations were particularly carried out in order to investigate the photo-catalytic activity and stability. Meanwhile the morphology, chemical composition as well as crystalline structure were investigated. It is found that the as-prepared Ag/AgCl/GO composite exhibited an ultrahigh photocatalytic activity and stability in the process of photodegrading RhB. The unique catalytic activity has been discussed based on the SPR effect in Ag nanoparticles on AgCl surface and the separation of photo-generated electron-hole pairs, the primary benefit of the stability owes a great deal to GO which can capture the photo-generated electrons in case they reduce Ag + ion or recombine the excited holes. [ABSTRACT FROM AUTHOR]

In this paper, bismuth oxybromide (BiOBr) nanosquares photocatalysts were synthesized via a facile hydrothermal method with the double regulation of the ionic liquid (IL) 1-hexadecyl-3-methylimidazolium bromide and ammonium bismuth citrate (BCA). To the best of our knowledge, this report is the first to describe the BiOBr material with simultaneous bismuth and halogen bidirectional source regulation. The structures, components, morphologies, optical properties and photocatalytic properties of the as-prepared samples were specifically explored. The photocatalytic ability was assessed using the degradation of rhodamine B under visible light irradiation. The BiOBr-IL + BCA exhibited improved photocatalytic activity compared with the BiOBr materials without double regulation. The primary active species were determined to be holes (h + ) and superoxide radicals ( O 2 − ) using electron spin resonance (ESR) analysis and free radical trapping experiments. This enhanced activity was attributed to its larger specific surface, the superior electron transfer ability, and the increased negative conduction band position, which favors the photogenerated electrons to trap the molecular oxygen to produce O 2 − . The production of more O 2 − can benefit the removal of pollutants. [ABSTRACT FROM AUTHOR]

In this paper, a novel visible-light responsive photocatalyst of Ag/AgCl@MIL-101 was synthesized via vapor diffusion-photoreduction strategy. The as-prepared composite material was characterized using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, ultraviolet–visible diffuse reflection spectra and X-ray photoelectron spectroscopy. Due to the synergistic effect between Ag/AgCl and MIL-101, the composite photocatalyst exhibited an enhanced and stable photoactivity for the degradation of Rhodamine B under visible light irradiation. The relationship between the photocatalytic activity and the structure of Ag/AgCl@MIL-101 hybrid material was discussed and the possible reaction mechanism was proposed. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO 2 ) bi-phasic powders with individual particles containing an anatase and rutile hetero-junction have been prepared using a sequential layer sol–gel deposition technique to soluble substrates. Sequential thin films of rutile and subsequently anatase TiO 2 were deposited onto sodium chloride substrates yielding extremely fragile composite layered discs that fractured into “Janus-like” like powders on substrate dissolution. Nitrogen doped and platinum sputtered analogues were also prepared, and analysed for photocatalytic potential using the photodegradation of Rhodamine B, a model organic pollutant under UV and visible light irradiation. The materials were characterised using X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, Raman spectroscopy and scanning electron microscopy. This paper sheds light on the relationship between anatase and rutile materials when in direct contact and demonstrates a robust method for the synthesis of bi-phasic nanoparticles, ostensibly of any two materials, for photocatalytic reactions or otherwise. [ABSTRACT FROM AUTHOR]

This paper reports the effect of different concentrations of Rosa ‘Andeli’ double delight petals aqueous extract (PERA) in the synthesis of silver nanoparticles (Ag-NPs), using an easy green chemistry method. Its kinetics study and photocatalytic activity were also evaluated. The Ag-NPs were obtained using an aqueous silver nitrate solution (AgNO 3 ) with 9.66% w/v, 7.25% w/v, and 4.20% w/v PERA as both reducing–stabilizing agent. The formation of the Ag-NPs was demonstrated by analysis of UV–vis spectroscopy, scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS) and transmission electron microscopy (TEM). TEM analysis shows spherical nanoparticles in shape and size between ∼0.5 and 1.4 nm. A comparative study was done to determine which concentration was the best reducing–stabilizing agent, and we found out that “ultra-small” nanoparticles (0.5–1.1 nm) were obtained with 9.66% w/v of PERA. The size of the Ag-NPs depends on the concentration of PERA and Ag(I). The reaction of formation of “ultra-small” Ag-NPs, proved to be first order for metallic precursor (silver) and second order for reducing–stabilizing agent (PERA). The Ag-NPs showed photocatalytic activity, in degradation of commercial dye with an efficiency of 95%. [ABSTRACT FROM AUTHOR]

In this paper, CdS/TiO 2 heteronanofibers have been prepared for the photocatalysis toward organic dyes under visible irradiation. Firstly, the one dimensional (1D) TiO 2 porous nanofibers (50–100) nm in diameter and several micrometers in length were synthesized by electrospinning and then CdS nanopaticles (50–100 nm in size) successfully grown onto TiO 2 fibers to form the heterostructure. These CdS/TiO 2 heteronanofibers were adopted as photocatalyst and the photocatalsis processes were analyzed in detail, showing the enhanced visible photodecomposition and good recycle ability. Furthermore, the degradation kinetics was further investigated by varying the amount of CdS. The increase of CdS component may enhance the degradation rate under visible light, but the total degradation efficiency also is affected by the adsorption capacity of catalyst toward the dyes. With the improved visible light degradation performance, these CdS/TiO 2 heteronanofibers would be expected to be used in water purification. [ABSTRACT FROM AUTHOR]

Both theories and experiments show that surface hydroxyl radicals ( OH) are the most important intermediate species in the photocatalytic process. As a source of OH, surface hydroxyl (OH) groups play an important role in its generation. In this paper, the OH groups were divided into surface acidic hydroxyl (OH(a)) and surface basic hydroxyl (OH(b)) groups. From the detection by a method of surface acid–base, ion-exchange reactions, the total surface density of OH groups was about 9.58 × 10 −5 mol m −2 . The results measured by Fourier transform infrared spectroscopy, 1 H magnetic-angle spinning NMR and electron spin resonance techniques demonstrated that the role of OH(a) groups was greater than that of OH(b) groups on the generation of OH radicals. By degradation of methyl orange, rhodamine B and p-chlorophenol, the photocatalytic activities of the catalysts were directly influenced by the amount of OH groups. [ABSTRACT FROM AUTHOR]

[Display omitted] Ti-based Metal–organic frameworks (Ti-MOF) have been extensively investigated for producing hydrogen via solar water splitting, while their intrinsic activities are still retarded by the poor performance of photocarriers separation and utilization. Herein, a donor-acceptor (D-A) supramolecular photocatalyst is successfully constructed via encapsulating fullerene (C 60) into MIL-125-NH 2 and meanwhile depositing individual Pt atoms as cocatalyst. The as-prepared C 60 @MIL-125-NH 2 -Pt exhibits remarkable activity in photocatalytic water splitting, with a H 2 formation rate of 1180 μmol g−1 h−1, which is ∼ 12 times higher than that of the pristine MIL-125-NH 2. Further investigations indicate that the host-guest interactions between C 60 and MIL-125-NH 2 strengthen the built-in electric field, which greatly facilitates the separation and migration of photogenerated charge carriers. In addition, the cocatalyst of individual Pt atoms not only further promotes the separation and transport of carriers but also enhances the contact between water and the catalyst. All of these factors directly contribute to the superior activity of C 60 @MIL-125-NH 2 -Pt. This work provides a new perspective for constructing D-A supramolecular photocatalysts for enhanced charge separation and making full use of photoelectrons to realize efficient hydrogen production. [ABSTRACT FROM AUTHOR]

[Display omitted] Covalent organic frameworks (COFs) with controlled porosity, high crystallinity, diverse designability and excellent stability are very attractive in metal-free heterogeneous photocatalysis of volatile organic compounds (VOCs) degradation. In order to construct the high optimal performance COFs under feasible and universal conditions, herein, the visible light-driven hollow COF TAPB-PDA (H-COF TAPB-PDA) microcapsule was designed by a facile dual-ligand regulated sacrificial template method. The H-COF TAPB-PDA microcapsule possesses improved surface area, high crystallinity, broad absorption range and high stability, which enables enhanced substrates and visible light adsorption, photogenerated electrons-holes separation and transfer, and facilitate the generation of reactive radicals. Importantly, it was found to be a highly efficient photocatalyst for toluene degradation under visible-light irradiation compared with the solid COF TAPB-PDA , and the degradation efficiency of toluene reached 91.8 % within 180 min with the conversion rate of CO 2 was 68.9 %. Additionally, the H-COF TAPB-PDA presented good recyclability and long-term stability after multiple photocatalytic reuses. Furthermore, the active sites of H-COF TAPB-PDA in photocatalytic degradation of toluene was proposed by XPS and DFT calculations, and the degradation pathway and mechanism was proposed and analyzed. The result presented great prospect of morphologic design of hollow COFs in metal-free heterogeneous photocatalysis for VOCs degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Impacts of RH, concentration and intermediate on HCHO photooxidation were studied. • DFT adsorption and photocatalytic simulations combined with multifactor assessment. • Enhanced and then weakened HCHO adsorption and catalysis caused an optimal 50% RH. • Dominant catalysis weakened with increasing concentration hindered HCHO oxidation. • By forming formate, two opposite actions caused nearly stable HCHO oxidation rate. Environmental factors affecting the photocatalytic oxidation of volatile organic compounds (VOCs) have previously been studied experimentally, but there are few theoretical studies, especially those on surface intermolecular forces. Because of this, it is unclear how multiple coexisting factors impact photocatalytic processes. Herein, comprehensive multi-factorial impact mechanisms of the photocatalytic oxidation of formaldehyde were assessed using experiments and density functional theory simulations. The influence of humidity, concentration, and intermediate formate was investigated using a nano-TiO 2 colloid, followed by adsorption and photocatalytic simulations. The maximum photocatalytic reaction rate and degradation efficiency occurred at 50% humidity due to the initially enhanced and then weakened adsorption and photocatalysis of formaldehyde. This stemmed from the increased number of water molecules and the narrower TiO 2 band gap at low humidities, as well as the competitive adsorption between formaldehyde and excess water molecules at high humidities. Upon increasing the formaldehyde concentration, its photocatalytic oxidation rate increased due to enhanced adsorption, but weakened photocatalysis decreased the photocatalytic efficiency. The intermediate formate enhanced the adsorption and inhibited photocatalysis and did not significantly change the photocatalytic oxidation rate of formaldehyde upon changing the irradiation time. These findings provide guidance for the photocatalytic oxidation of VOCs produced by industrial air pollution. [ABSTRACT FROM AUTHOR]