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A series of covalent organic frameworks (COFs) with β‐ketoenamine linkages named TpTt‐COF, TAPT‐COF, and TpPa‐1 were constructed for photocatalytic H2O2 generation in pure water and ambient air under visible light. Among them, TpTt‐COF performed striking H2O2 yield of 2647 μmol L−1, which is 3.5, 17.5, and 176.5‐fold those of TAPT‐COF, TpPa‐1, and bulk g‐C3N4, respectively, attributing to the electron‐deficient trait, short charge diffusion distance, and the narrowest bandgap of TpTt‐COF. Additionally, to achieve the facile recovery, TpTt‐COF was firmly and evenly anchored on melamine sponges (MS) because plenty of amino groups on the surface of MS could be involved in the β‐ketoenamine formation and guide the synthesis of TpTt‐COF on MS. The corresponding H2O2 evolution over this photocatalyst monolith is also respectable and can be well repeated at least four times. This work is quite instructive for photocatalyst construction based on covalent organic frameworks and facile photocatalytic applications. [ABSTRACT FROM AUTHOR]

Photocatalytic conversion of biomass‐derived 5‐hydroxyfurfural (HMF) to value‐added 5‐hydroxymethyl‐2‐furancarboxylic acid (HMFCA) is an environmentally friendly process. Here, Ag nanoparticle (NP) supported on TiO2 (Ag/TiO2) materials with different interfacial structures were fabricated via incipient wetness impregnation. In the photocatalytic oxidation of 5‐HMF to HMFCA, low‐temperature reduction (473 K) on Ag/TiO2 could improve the photoinduced charge separation efficiency and promote the reaction due to the "enhanced" localized surface plasmon resonance (LSPR) effects achieved through strong metal–support interaction (SMSI). In particular, 2.5 % Ag/TiO2‐LTR exhibited superior performance with an HMFCA selectivity of up to 96.7 % under visible‐light illumination. In contrast, the photocatalytic efficiency was greatly reduced when the reduction temperature increased to 773 K because of the encapsulation of Ag NPs by a thicker TiOx overlay, which significantly weakened visible‐light harvesting. Overall, these findings offer an efficient methodology for designing interfacial enhanced plasmonic photocatalysts for the valorization of biomass. [ABSTRACT FROM AUTHOR]

Flower-like BiOI was decorated by CdS nanodots and followed by the introduction of iodine vacancies (V I) for photocatalytic sodium lignosulfonate (SLS) valorization under visible light. The iodine vacancies could adjust the band configuration, strengthen the light absorption and act as electron traps, while the intimate contact between BiOI and CdS nanodots provides a high-speed channel for charge transfer. As a consequence, the photocatalytic performance of SLS conversion into value-added vanillin was greatly improved over CdS/BiOI-V I compared with those of CdS, BiOI and CdS/BiOI. The highest yield of vanillin is 10.95 mg/g SLS over CdS/BiOI-V I , about 5, 8.7, 1.3 times those of CdS, BiOI, CdS/BiOI, respectively, and exceeding most related photocatalysts reported elsewhere. More significantly, as to the lignin from Masson pine and alkali lignin, the corresponding vanillin yield can reach 7.04 and 6.54 mg/g lignin , respectively, under the same condition, which suggests the great potential and universality for photocatalytic lignin valorization over such CdS/BiOI-V I heterostructure. [ABSTRACT FROM AUTHOR]

The delicate design of photocatalyst monoliths is of great significance for the practical applications of artificial photocatalysis. An in-situ synthesis to prepare ZnIn 2 S 4 /cellulose foam was developed. Cellulose is dispersed in a highly concentrated ZnCl 2 aqueous solution to prepare Zn2+/cellulose foam. Zn2+ ions are pre-anchored by hydrogen bonds on cellulose and become in-situ sites for synthesizing ultra-thin ZnIn 2 S 4 nanosheets. This synthesis method makes ZnIn 2 S 4 nanosheets and cellulose tightly bound and prevents ZnIn 2 S 4 nanosheets from stacking in multiple layers. As a proof of concept, the prepared ZnIn 2 S 4 /cellulose foam exhibits a favorable performance for photocatalytic reduction of Cr(VI) under visible light. By adjusting the concentration of zinc ions, the optimal ZnIn 2 S 4 /cellulose foam is capable to completely reduce Cr(VI) in 2 h and the photocatalytic activities show no decrease after 4 cycles. This work could inspire people to build floating cellulose-based photocatalysts via in-situ synthesis. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Core-shell Bi-MOF@BiOX is fabricated by a one-pot solvothermal strategy. • The competitive coordination effect to Bi3+ makes BiOX and Bi-MOF contact closely. • Bi-MOF@BiOX has nice activities on Cr(VI), tetracycline and o-nitrophenol removal. • For above reactions, more than 13, 7, 5-time enhancements of activity are achieved. • Enhanced activities are observed for the treatment of mixed pollutants. Core-shell Bi-MOF@BiOX (X = I, Br and Cl) hybrids were fabricated by a one-pot solvothermal strategy via regulating the concentration and type of halogen ions in the Bi-based CAU-17 synthesis. By virtue of the competitive coordination effect to Bi3+ between CAU-17 and BiOX, CAU-17 was converted into another Bi-MOF with similar structures and compositions. Moreover, Bi3+ plays the role of "bridge" and endows an intimate interface contact between BiOX and the Bi-MOF, which immensely expedites the charge and mass transportation. The obtained Bi-MOF@BiOX hierarchical heterostructures were applied to photocatalytic elimination of solo and mixed pollutants (Cr(VI)/tetracycline and Cr(VI)/o-nitrophenol), and exhibited favorable performances. Choosing Bi-MOF@BiOI as a typical example, the corresponding performances for Cr(VI) reduction, tetracycline and o-nitrophenol degradation in their solo systems are 14, 10, 8 times higher than those of CAU-17, and 13, 7, 5 times higher than those of BiOI under visible light, respectively. Of note, the above photocatalytic performances could be further improved in the coexisting environment of Cr(VI) and tetracycline or o-nitrophenol, which is attributed to the elevated charge separation efficiency caused by the timely consumption of photo-excited electrons and holes. This work gives some insights into the delicate design of MOF photocatalysts and their applications in environmental restoration. [ABSTRACT FROM AUTHOR]

Photocatalytic H 2 O 2 production by reducing O 2 has drawn great interest, but most reactions were conducted in pure O 2 which requires extra energy input. Here, TpPa-1 was facilely decorated by ZnIn 2 S 4 nanosheets for H 2 O 2 production in ambient air under visible light. Profiting from the hierarchical heterostructure, efficient visible-light absorption and O 2 capture of ZnIn 2 S 4 /TpPa-1, an H 2 O 2 yield of 516 μmol·L−1 was obtained with 2 h irradiation, which is 3.0 and 3.9 times those of blank TpPa-1 and ZnIn 2 S 4 , respectively. The intimate interface contact between ZnIn 2 S 4 and TpPa-1 also contributes to the performance improvement. It is noted that the photocatalytic H 2 O 2 formation over ZnIn 2 S 4 /TpPa-1 hybrids experienced an indirect reduction of O 2 that ·O 2 - served as the key intermediate. Additionally, the reactions under different atmospheres and ethanol concentrations demonstrate that both O 2 and ethanol play important roles in the efficient evolution of H 2 O 2. This work could enlighten the heterostructure construction and (photo)catalytic H 2 O 2 production based on covalent organic frameworks. [Display omitted] • ZnIn 2 S 4 /TpPa-1 was first constructed for photocatalytic H 2 O 2 evolution in air. • The H 2 O 2 yield is 3 and 3.9 time-enhancement than those of ZnIn 2 S 4 and TpPa-1. • Efficient visible-light absorption and O 2 capture lead to the high activity. • The H 2 O 2 formation over ZnIn 2 S 4 /TpPa-1 undergoes an indirect reduction of O 2. [ABSTRACT FROM AUTHOR]

The reduced graphene oxide (RGO) loaded Zn 0.5 Cd 0.5 S nanocomposite has been successfully prepared by a facile solvothermal method. The as-prepared photocatalysts were characterized by a combination of X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and N 2 absorption-desorption. The Zn 0.5 Cd 0.5 S@RGO composites with a RGO content of 0.5 wt% (GS-0.5) showed the highest photocatalytic activity for the degradation of various dyes (methylene blue, methyl orange and Rhodamine B), which is mainly due to the uniform dispersion of nanoparticles on RGO sheets and the enhanced separation rate of photo-induced electrons and holes. The GS-0.5 photocatalyst can be repetitively used without significant loss of activity. This new material holds great promise for applications in the field of water purification as well as optoelectronic fields at a large scale. [ABSTRACT FROM AUTHOR]

A facile and simple method was offered to synthesize porous N-doped ZnO via direct calcination of urea and ZIF-8 mixture. From XRD and XPS analysis, nitrogen has been successfully incorporated into ZnO lattices without introducing other N-containing or Zn-containing phases. Such nitrogen doping can enhance the visible-light harvesting ability and inhibit the recombination rate of electron-hole pairs; as a result, improved visible-light driven photocatalytic activity was achieved in N-doped porous ZnO and the photocatalytic activity of N-doped ZnO is 2.58 times higher than that of ZIF-derived pure ZnO. [ABSTRACT FROM AUTHOR]

N-doped titania is prepared using ethylenediamine as the nitrogen source by a sol–gel method. The preparation conditions, such as the volume ratio of ethylenediamine to sol, and the heat temperature on the nitrogen doping are systematically examined. UV results indicate the N-doped TiO 2 catalysts have enhanced absorption in the visible light region, and exhibit high activities on the visible light photocatalytic reactions to the hydrogen production and methyl orange degradation. X-ray diffraction (XRD) and FT-IR results reveal that N species have been incorporated into the TiO 2 lattice at a high N-doping level. N-doped titania prepared with an ethylenediamine to sol volume ratio of 1:1 and sintering temperature of 500 °C performed the highest hydrogen production rate (2.98 mmol g −1 h −1 ) and best methyl orange degradation performance. A conceivable structure change of N-doped TiO 2 sintered at different temperature was proposed. [ABSTRACT FROM AUTHOR]

• This work reports highly crystalline S-doped CNNTs with tunable geometry. • S-CNNTs-20 exhibit an enhanced visible-light photocatalytic N 2 fixation rate. • High crystallinity and S-N coordination firmly stabilize the surface N in S-CNNTs-20. • The synergistic effect is due to high crystallinity, S dopant and holey tubular form. Highly crystalline carbon nitride nanotubes doped with sulfur (S-CNNTs) were obtained from a facile co-polymerization of thiourea and melamine precursors. The geometry, crystallinity and the doped S content in CNNTs can be fine-tuned by varying the content of thiourea. Under the addition of 20 wt% thiourea, the resulting highly condensed S-CNNTs have a diameter of around 20 nm with mesopores on the tube wall, presenting an optimal visible light photocatalytic ammonia yield rate of 0.64 mM g cat –1h−1 with an apparent quantum efficiency of 5.65% at 420 nm. The surface N atoms in the optimal photocatalyst can be firmly stabilized due to the increased crystallinity and S-induced coordination. The high crystallinity and one-dimensional mesoporous structure promote the electron transfer along the longitudinal dimension, facilitate mass transport and extend visible light harvesting. The mesoporous nanotubes favor the exposure of S dopant active sites for the chemisorption and activation of nitrogen molecules. Moreover, the photoreduction ability is improved due to the upshifted conduction band level after S doping. The designed structure maximizes the utilization of the synergistic effect, thereby improving the photocatalytic activity. This work may provide a reliable and promising way to regulate the morphology and electronic structure of tubular CN for highly efficient photocatalysis via a nonmetal doping approach. [ABSTRACT FROM AUTHOR]

• BiOI/MIL-121 photocatalyst is constructed by a facile hydrothermal method. • BiOI/MIL-121 performs excellently for tetracycline degradation under visible light. • Free carboxyl in BiOI/MIL-121 can adsorb tetracycline through hydrogen bond. A series of BiOI/MIL-121(Al) hybrid photocatalysts has been prepared by a facile hydrothermal method. Two-dimensional BiOI sheets are intimately anchored on rod-like MIL-121 due to the electrostatic and coordination effects between Bi3+ and carboxyl. The BiOI/MIL-121(Al) hybrid exhibits favorable performances for visible-light-driven degradation of tetracycline. The degradation performance of the optimal sample BM-20 is more than twice as that of pure BiOI. Apart from the close contacts between BiOI and MIL-121, the hydrogen bond induced by carboxyl in MIL-121 promotes the adsorption of tetracycline, which is also conducive to the photocatalytic degradation process. Moreover, results show that photo-induced holes and superoxide radicals are both the main active species for the photocatalytic degradation of tetracycline over BiOI/MIL-121 composites. This work would inspire the materials design with specific functional groups for efficient (photo)catalytic reaction. [ABSTRACT FROM AUTHOR]

• PEGylated deep eutectic solvent is used for mild synthesis of CdS. • Core-shell CdS@CeO 2 photocatalyst was successfully synthesized. • The degradation of tetracycline is as high as 91.5% by optimal photocatalyst. • CeO 2 coating helps effectively reduce the photo-corrosion. As ionic liquid analogues, deep eutectic solvents (DESs) have been widely used in many fields in past decades. In this work, a PEGylated deep eutectic solvent (PEGylated DES) was used for the solvothermal synthesis of CdS@CeO 2 core-shell material for the first time. The amount of CeO 2 coating has a remarkable influence on the photocatalytic degradation of tetracycline. When the molar ratio of CeO 2 to CdS is 1:1, the degradation rate of tetracycline is 91.5% under visible light (λ > 420 nm), which is about 1.57 and 10.5 times as that of CdS and CeO 2 , respectively. The enhancement of photocatalytic performance is due to the fast separation of photogenerated electrons, the lower recombination of electron-hole pairs and the smaller band gap, which are demonstrated via UV–vis diffuse, photocurrent density, electrochemical impedance spectroscopy, photoluminescence and Mott-Schokkty measurements. This work provides a new way for the design of a core-shell metal sulfide photocatalyst that can be used in environmental remediation. [ABSTRACT FROM AUTHOR]