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Graphical abstract Highlights • Ti-MOFs decorated by Pt or Au NPs with sizes of 3–9 nm have been synthesized. • Pt/MIL-125-NH 2 showed highest photocatalytic activity for alcohol oxidation. • M/MIL-125-NH 2 exhibited much better photocatalytic activity than that of M/MIL-125. Abstract Metal nanoparticles (NPs) decorated MOFs for photocatalysis has drawn enormous attention in the past decade. Here, a series of M/Ti-MOFs (M = Pt and Au, Ti-MOFs = MIL-125-NH 2 and MIL-125) has been synthesized through a facile post-synthetic method and the metal NPs highly dispersed on surface of MOFs with major sizes of 3–9 nm. Light absorption edges of scaffolds are crucial in the photocatalytic oxidation of benzyl alcohol over M/MIL-125-NH 2 and M/MIL-125. The conversion of benzyl alcohol over Pt/MIL-125-NH 2 is 2.4 times and 1.9 times higher than that of pristine MIL-125-NH 2 and Au/MIL-125-NH 2 , respectively. Besides, Pt/MIL-125-NH 2 photocatalyst also exhibited good activity for Cr(VI) reduction compared to that of MIL-125-NH 2. The enhanced photocatalytic activity of Pt/MIL-125-NH 2 is contributed to the rapid transfer of photo-induced electrons and decreased recombination of electron-hole pairs, which is verified by measurements of photocurrent and Electrochemical Impedance Spectroscopy. We hope that this study will provide worthy information for designing metal/MOFs or metal/MOFs-NH 2 photocatalysts. [ABSTRACT FROM AUTHOR]

A novel and highly efficient photocatalyst of Cd 0.5 Zn 0.5 S@ZIF-8 nanocomposite has been developed by a facile self-assembly strategy. This is the first report on the application of Cd x Zn 1−x S and metal-organic framework (MOF) nanocomposite as photocatalysts for the reduction of Cr(VI). The resulting Cd 0.5 Zn 0.5 S@ZIF-8 exhibited higher photocatalytic activity than that of pristine Cd 0.5 Zn 0.5 S and ZIF-8. Particularly, the CZS@Z60 composite with 60 wt% of ZIF-8 exhibited a photocatalytic activity that is about 1.6 times as high as that of Cd 0.5 Zn 0.5 S. The dominant reason for the improved photocatalytic reduction potential is proved to be the newly-formed interfacial S Zn bonds that firmly connect Cd 0.5 Zn 0.5 S and ZIF-8 and substantially improve the separation efficiency of photo-excited electrons and holes. The newly-formed chemical bonds are confirmed by XPS analyses, and the prolonged lifetime of photo-excited electrons is evidenced by the electrochemical measurement of photocurrent, which shows that the photocurrent on Cd 0.5 Zn 0.5 S@ZIF-8 is much higher than that of Cd 0.5 Zn 0.5 S and ZIF-8. This study clearly demonstrates that the MOF-based composite nanomaterials hold great promises for applications in the field of environmental remediation and for design of novel photocatalytic materials. [ABSTRACT FROM AUTHOR]

MIL-101(Cr)@ZnIn 2 S 4 hierarchical heterojunction was delicately designed and fabricated through the in-situ growth of ZnIn 2 S 4 on MIL-101 and electrostatic self-assembly. It is affirmed that the Cr–S interface bonding between MIL-101 and ZnIn 2 S 4 in their composite was established based on the characterization results of X-ray photoelectron spectroscopy, Raman and zeta potential. Thus, a high-speed channel for charges transfer is offered due to the Cr–S bond, intimate interface contact and hierarchical structure of MIL-101@ZnIn 2 S 4 , which largely inhibits the recombination of photo-induced charge carriers and promises a remarkable photocatalytic activity. Choosing visible-light-driven reduction of Cr(VI) as a model, the optimal MIL-101@ZnIn 2 S 4 sample can reduce 95% of Cr(VI) within 30 min, corresponding to a rate constant of 0.107 min−1, which is 2.9-fold compared with blank ZnIn 2 S 4 counterpart (MIL-101 has a negligible performance). Additionally, a conspicuous apparent quantum yield of 9.7% can be achieved at a wavelength of 420 nm. Eventually, to reinforce the practicability of MIL-101@ZnIn 2 S 4 , the composite powders were manufactured as aerogels utilizing bacterial cellulose as a substrate. The MIL-101@ZnIn 2 S 4 aerogel still exerts an enviable performance for photocatalytic reduction of Cr(VI) and stability. This work could inspire the material design and environmental remediation based on MOFs. [Display omitted] • MIL-101@ZnIn 2 S 4 hierarchical heterojunction with Cr–S bonds was delicately designed. • A high-speed channel for charges transfer is presented over MIL-101@ZnIn 2 S 4. • Efficiently photocatalytic reduction of Cr(VI) is achieved over MIL-101@ZnIn 2 S 4. • Aerogel was prepared from powder to improve the practicability of MIL-101@ZnIn 2 S 4. [ABSTRACT FROM AUTHOR]

In recent years, organic-inorganic composites have aroused considerable attention due to their tunable properties, where cellulose tailored semiconductors for artificial photocatalysis are typical examples. In virtue of the unique fibrous structure and abundant surface functional groups, cellulose employed in the design of photocatalysts could endow good hydrophilicity, dispersity, stability, high porosity, conductivity, large surface area and even unexpected morphologies. In this review, the modification strategies of cellulose to semiconductors (function as assistants and sacrifice as bio-templates), diverse monoliths (films, gels and textiles) and their photocatalytic applications (contaminants treatment and H 2 production) are summarized in detail. In addition, the challenges and outlook of semiconductor/cellulose photocatalysts are also discussed. • Cellulose tailored semiconductors for photocatalysis were summarized in detail. • Two strategies including cellulose as assistant and bio-template were introduced. • Diverse semiconductor/cellulose photocatalyst monoliths were depicted. • Various photocatalytic applications over semiconductors/cellulose were described. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate framework-8 (ZIF-8) crystals were obtained by an electric current-assisted synthesis method with stoichiometric Zn2+ and 2-methylimidazole precursors. The resulting ZIF-8-CS2 shows enhanced CO 2 adsorption performance (31.2 cm3/g) with CO 2 /N 2 selectivity of 9 at 273 K, while ZIF-8 prepared without electric current assistance shows CO 2 adsorption of 18.4 cm3/g and CO 2 /N 2 selectivity of 5. The increased CO 2 adsorption ability is ascribed to the high specific surface area and total pore volume of ZIF-8-CS2. • Fine ZIF-8 powder (ZIF-8-CS) was obtained by electric current-assistance method. • ZIF-8-CS owns bigger specific surface area and total pore volume. • ZIF-8-CS shows better CO 2 adsorption ability and CO 2 /N 2 adsorption selectivity. [ABSTRACT FROM AUTHOR]

Mesoporous TiO 2 with regular pancake-like morphology was synthesized by facile calcination of MIL-125 (MIL = Materials of Institut Lavoisier) at different temperatures. The optimal sample MT400 (calcination at 400 °C) is composed of nanoparticles with a size of about 10 nm and mesopores of about 4–12 nm. Its specific surface area can reach up to 174 m2 g−1. In the photocatalytic conversion of sodium lignosulfonate, the yield of vanillin over MT400 is 2.1 mg/g, obviously superior to that over P25 TiO 2 (0.27 mg/g). MT400 with a large specific surface area offers sufficient active sites, and its mesoporous structure provides pathways for the transport of charge carriers and products, giving a satisfactory photocatalytic performance for vanillin generation. It is proved that h+ and ·O 2 − play the key role for vanillin generation from sodium lignosulfonate. This work indicates that MOF-derived metal oxides hold great promise in the application of biomass (photo)catalytic valorization. [Display omitted] • A pancake-like mesoporous TiO 2 was synthesized by the calcination of MIL-125. • MT400 is composed of particles with a size of ca. 10 nm and mesopores of 4–12 nm. • The yield of vanillin over MT400 is 7.7-fold higher than that of P25. • The structure is helpful to the transport of charge carriers, substrates and products. [ABSTRACT FROM AUTHOR]

• Cd x Zn 1-x S/ZnO nanocomposites were readily fabricated via a facile one-pot method. • The Cd/Zn molar ratios were tuned by altering the amounts of Na 2 S and Na 2 S 2 O 3. • Cd x Zn 1-x S/ZnO showed glorious performance on photocatalytic reduction of Cr(VI). • Cd 0.68 Zn 0.32 S/ZnO nanoparticles have tiny diameters of about 5−8 nm. Cd x Zn 1-x S/ZnO nanohybrids were fabricated by using mixed Na 2 S and Na 2 S 2 O 3 as the sulfur source via a facile one-pot synthesis. Cd x Zn 1-x S/ZnO with x = 0.54, 0.58, 0.62, 0.68 and 0.75 was successfully tuned by altering the molar ratio of Na 2 S and Na 2 S 2 O 3. Sole sulfur source Na 2 S or Na 2 S 2 O 3 could only generate Cd 0.5 Zn 0.5 S or CdS/ZnO, respectively. The in-situ co-growth of Cd x Zn 1-x S and ZnO makes them combine penetratingly in Cd x Zn 1-x S/ZnO nanohybrids, giving them a highly intimate contact. The natural matched band-edge positions and highly intimate contacts between Cd x Zn 1-x S and ZnO are conductive to charge separation and transfer. Benefiting from the structural and compositional merits, the optimized Cd x Zn 1-x S/ZnO nanohybrid with sizes of about 5−8 nm exhibited outstanding performance for Cr(VI) reduction under visible-light illumination. The newly designed one-pot synthetic strategy in this work may provide a brand-new pathway in developing high-efficiency multi-component photocatalysts for practical use. [ABSTRACT FROM AUTHOR]

Industrial effluents often contain mixed metal ions and dyes, and it is difficult to efficiently remove both types of contaminants simultaneously. Here, MIL-125-NH 2 @Ag/AgCl composites were for the first time developed through a facile deposition-photoreduction method for simultaneously removing Cr(VI)/Rhodamine B (RhB)/Malachite Green (MG) ternary system pollutants under visible-light irradiation. The capacities of Cr(VI) reduction dramatically increased to 98.4% in the coexistence of RhB and MG compared to that of binary (Cr(VI)/RhB (69.6%) or Cr(VI)/MG (67.5%)) and single Cr(VI) (29%) systems. In the meantime, the degradation efficiencies of dyes especially RhB in the ternary system were also improved compared to that of their individual systems. On the grounds of all the experimental results, it can be concluded that the efficient light-harvesting and electrons migration in MIL-125-NH 2 @Ag/AgCl and the synergistic effect of redox reactions between Cr(VI) and dyes hinder the recombination of photo-induced electron-hole pairs, which are responsible for their high photocatalytic activity to eliminate the mixed pollutants. This study provides a new route to construct high-performance photocatalysts for the practical treatment of wastewater containing mixed pollutants. • Photocatalytic Cr(VI) reduction highly enhanced as MIL-125-NH 2 combined with Ag/AgCl. • Cr(VI) reduced capacities improved 3.4 times in the coexistence of RhB and MG. • Dyes degraded activities also increased in the presence of Cr(VI). • Efficient light-harvesting, charge transfer and synergistic effect of redox cause it. [ABSTRACT FROM AUTHOR]

• TiO 2 /ZnIn 2 S 4 nanocomposites were constructed by a facile one-pot synthesis. • The unique embedded structure of TiO 2 /ZnIn 2 S 4 was constructed. • TiO 2 /ZnIn 2 S 4 displays an excellent photocatalytic activity of Cr(VI) reduction. • The survival time and migration rate of photo-generated electrons were enhanced. Various TiO 2 /ZnIn 2 S 4 composites with an embedded structure have been developed by a facile one-pot synthesis. The activities of all samples were estimated by photocatalytic reduction of Cr(VI) under visible light (λ>420 nm). Results showed that the electrostatic interaction and self-assembly effect make TiO 2 nanoparticles inserting into ZnIn 2 S 4 nanosheets. The resulting TiO 2 /ZnIn 2 S 4 composites show much better photocatalytic performance for Cr(VI) reduction than that of pristine TiO 2 and ZnIn 2 S 4. Especially, the photocatalytic efficiency of T/ZIS-0.3 (TiO 2 loading of 30 wt%) is approximate 3 times as high as that of pristine ZnIn 2 S 4 (TiO 2 exhibited almost no activity). The embedded structure of TiO 2 /ZnIn 2 S 4 offers apparent increase of specific surface area, visible-light absorption and electrons transfer efficiency, which are responsible for the boosted photocatalytic activity. This work would inspire researchers to construct high-efficiency semiconductor composites for photocatalytic environmental governance. [ABSTRACT FROM AUTHOR]

Porous carbon was prepared through a simple and efficient method using microcrystalline cellulose as carbon source. Compared with pristine carbon (C-1), nitric acid treated carbon (C-2) has more acidic oxygen-containing groups on its surface (acid density: 0.14 mmol/g for C-1 and 2.13 mmol/g for C-2). Pt supported Pt/C-2 behaves a substantially enhanced catalytic oxidation activity of benzyl alcohol (conversion of 71.7%) compared with Pt/C-1(conversion of 37.2%) under the same conditions. Further characterizations and experiments indicate that the excellent dispersion of Pt nanoparticles and strong hydrogen bonding interaction between benzyl alcohol and Pt/C-2 are crucial for the enhanced catalytic activity. Our experimental results also show that mild temperature (60 °C) and non-polar solvents are more beneficial for the reaction, and O 2 atmosphere is a necessity for benzyl alcohol oxidation. Image 1 • Porous carbon was prepared from microcrystalline cellulose. • Nitric acid treated carbon (C-2) has more acidic oxygen-containing groups. • Pt/C-2 has enhanced catalytic activity for benzyl alcohol oxidation. • The role of acidic oxygen-containing groups were explained. [ABSTRACT FROM AUTHOR]

Lignin is abundant and contains a large number of aromatic groups. Herein, Cd x Zn 1-x S photocatalyst with tunable band gap energy was successfully synthesized by using 3-mercaptopropionic acid as a structure tuning additive. Cd x Zn 1-x S can depolymerize alkaline lignin to vanillin by the photocatalytic process. Each gram of alkaline lignin can produce 46.5 mg of vanillin. 2-Phenoxy-1-phenylethanol (PP-ol) and other model compounds were used to understand the depolymerizing process of lignin. Fine tuned Cd x Zn 1-x S can effectively cleave the C β -O-4 bond existed in PP-ol under simulated sunlight. The highest conversion of PP-ol was 89.5% with phenol and acetophenone yields of 66.2% and 33.5%, respectively. The mechanism studies confirm that the C α -H in PP-ol and lignin is firstly dehydrogenated to form C α radical intermediates, and then the photogenerated electrons break the adjacent C β -O bond. This research provides a new strategy to prepare valuable chemicals by virtue of renewable biomass and simulated sunlight. [ABSTRACT FROM AUTHOR]

Catalytic conversion of lignin to certain aromatic compounds has been extensively studied but still has great challenges. Photocatalytic depolymerizing lignin is a very promising method to obtain valuable chemicals. Herein, Zn 4 In 2 S 7 (ZIS)-based photocatalyst was successfully synthesized by simply combining ZIS and graphene oxide (GO). Photocatalyst ZIS-100 can efficiently depolymerize organosolv lignin into phenols and ketones. The relative content of valuable compounds in the depolymerized product was increased by 2.5 times as compared that without photocatalyst. The photocatalyst can effectively break C β -O bonds in 2-phenoxy-1-phenylethanol (PP-ol, a model compound) and the conversion of PP-ol is 93.27%. Mechanism studies show that the thiol groups on the surface of ZIS-100 play an important role in the formation of C α radical intermediates. Photocatalytic cleavage of C β -O bond mainly follows a one-step reaction mechanism through a self‑hydrogen transfer process. This study provides a new strategy for selectively breaking C β -O bond in lignin to form valuable chemicals. [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]

Abstract In this study, homogeneous alloy Au Pt nanoparticles were successfully immobilized on ultrathin TiO 2 nanorods via a facile photodeposition technique. The Au Pt/TiO 2 hybrid exhibited high photocatalytic activity and stability during the selective photosynthesis of benzaldehyde from benzyl alcohol under visible light. The optimal performance was obtained with the Au 1 Pt 1 /TiO 2 sample, which had a benzyl alcohol conversion rate of 65.3%. The engineered TiO 2 nanorods (304 m2/g) can be employed as a stabilizing matrix and an excellent dispersant for noble metal particles. Moreover, the formation of the alloy structure substantially enhances the photoinduced carrier separation efficiency compared with loading Au or Pt alone on TiO 2. The bimetallic nanoparticles exhibited the properties related to the individual metals, as well as new properties due to synergistic effects of the electron-accumulating function of Pt and the surface plasmon resonance of Au. Graphical abstract Image 1 Highlights • Au Pt alloy successfully immobilized on ultrathin TiO 2 nanorods. • Au Pt/TiO 2 exhibited enhanced photocatalytic performance and good stability. • Benzyl alcohol conversion rate was 65.3% in the presence of Au 1 Pt 1 /TiO 2. [ABSTRACT FROM AUTHOR]

Abstract ZIF-8 wrapped two-dimensional ZIF-L(Co) was prepared. By adjusting the Zn2+ concentration in precursor, ZIF-8 layer with different thickness was coated onto sheet-like ZIF-L. After carbonization, hierarchical porous carbon with CNTs wrapping was formed. Proper ZIF-8 coating would result in the porous carbon with relative high BET surface area, N content, electrical conductivity and proper pore size distribution; thus showing higher supercapacitive performance than that of carbonized ZIF-8 or carbonized ZIF-L. The highest specific capacitance is 274 F/g for carbonized composite materials compared to that of 220 F/g for carbonized ZIF-8 and 57 F/g for carbonized ZIF-L. Moreover, such composite sample (CZ-6) showed high stability and the energy density reached 6.99 W h/kg at a power density of 0.262 kW/k, which is better than most of other ZIF-based porous carbon reported before. Graphical abstract Image 1 Highlights • ZIF-8 wrapped Co-ZIF-L was synthesized and carbonized into core-shell carbon. • The core-shell structure combined the merits of carbonized ZIF-8 and ZIF-L. • ZIF-L could avoid the agglomeration of ZIF-8 and help the graphitization of carbon. • Carbonized ZIF-L@ZIF-8 shows the highest specific capacitance of 274 F/g. [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]

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]

Metal-organic frameworks (MOFs) have been widely explored as adsorbents for heavy metal ions removal. However, the recovery and regeneration of powdery MOFs remains a huge challenge. In this work, MIL-121 (Al-based MOF) crystals were incorporated into biodegradable alginate matrix to form composite beads with enhanced recyclability and adsorption capacity. A systematic adsorption test for Cu2+ and Cd2+ was conducted and the optimal sample (with a MOF loading of 50 wt%) presented an adsorption capacity of 204.5 mg/g for Cu2+ and 88.7 mg/g for Cd2+. Moreover, the composite beads can be regenerated effectively by hot water (80 °C). The desorption is attributed to the carboxyl-rich MIL-121, which could release massive protons (H+) at elevated temperature. Compared with the traditional desorption using strong acids, this chemical-free thermal desorption strategy holds a great potential for adsorbent regeneration and practical wastewater treatment. [Display omitted] • MIL-121 was integrated into biodegradable alginate to form composite beads. • The composite beads exhibited high heavy metal ion removal efficiency. • The composite bead can be recycled easily. • The composite beads can desorb heavy metal ions in 80 °C hot water. [ABSTRACT FROM AUTHOR]