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Photorefining of biomass and its derivatives to value-added chemicals is an alternative solution to address the global energy shortage and environmental issues. Herein, efficient and selective oxidation of 5-hydroxymethylfurfural (HMF, 91.1% conversion) to 2,5-diformylfuran (DFF, 99.4% selectivity) is demonstrated by visible light-driven photocatalysis over cocatalyst-free ZnIn2S4 nanosheets with crystal facet engineering. The spatial accumulation of photogenerated electrons and holes on the (110) and (102) crystal facets triggers a two-electron oxygen reduction reaction (2e-ORR) for H2O2 generation and HMF oxidation into DFF, respectively. The severe attenuation of photostability is caused by the irreversible photocorrosion of Zn–S with the formation of Zn–O chemical bonds by the formation of ˙OH from the in situ decomposition of H2O2. Spontaneous substitution of oxygen with sulfur has been proven to efficiently improve the photostability of ZnIn2S4. This present work provides insights into improving the durability of ZnIn2S4 and sheds new light on biomass valorization via photorefinery. [ABSTRACT FROM AUTHOR]

The effect of zeolite 3.7 ̊ A acidity on the reduction of surface deposition propensity of a Jet A-1 fuel, with marginal thermal oxidative stability was studied. This was achieved through treatment of the fuel in a packed bed reactor, using three types of monolithic zeolite with different Si/Al ratios. It was found that the increase of acidity is directly proportional to the surface deposition reduction such that the treatment with the highest ratio (Si/Al = 25) resulted in the most significant surface propensity reduction. However, a combination of zeolite with the lowest acidity (Si/Al = 17) and the activated carbon exhibited the greatest improvement of thermal oxidative stability. As a general trend, for all three Si/Al ratios in the monolithic zeolites used in this work, surface deposition propensity of the Jet A-1 fuel decreased markedly with the increase of monolithic size. Nevertheless, it is anticipated that efficacy will reach an steady state after a certain point. Quantum chemistry calculations demonstrate that polar species can interact with the CHA and 2Al doped chabazite in a number of ways, from dispersion interactions to forming covalent and hydrogen bonds. Furthermore, our calculations suggest that the doping CHA with Al enhanced the adsorption of polar species, which agree with a lab-scale experiment with the model fuel. • Improvement of Aviation Fuel Stability by Zeolite pre-Treatment. • Theoretical Investigation of Zeolite Fuel-Polar-Species Interactions. • Correlation/Validation of Experimental and Theoretical Work. • Application of Ab Initio Quantum Chemistry to Fuel Engineering. [ABSTRACT FROM AUTHOR]

The S-scheme W 18 O 49 /g-C 3 N 4 heterojunction multifunctional photocatalyst was synthesized, showing efficient and rapid photocatalytic hydrogen production, degradation (RhB) and bactericidal (E. coli) properties. The reasons for the improved photocatalytic performances were systematically analyzed. [Display omitted] • S-scheme W 18 O 49 /g-C 3 N 4 heterojunction multifunctional photocatalyst was developed. • S-scheme heterojunction improved carriers separation and redox ability of catalyst. • FDTD revealed the expanded light absorption intensity and range for W 18 O 49 /g-C 3 N 4. • The H 2 yield rate of W20-CNNT (4.67 mmol⋅g−1⋅h−1) is 15.1 times that of Bulk-CN. • W20-CNNT exhibited rapid photocatalytic degradation and bactericidal properties. The design of multifunctional photocatalyst with strong redox performance is the key to achieve sustainable utilization of solar energy. In this study, an elegant S-scheme heterojunction photocatalyst was constructed between metal-free graphitic carbon nitride (g-C 3 N 4) and noble-metal-free tungsten oxide (W 18 O 49). As-established S-scheme heterojunction photocatalyst enabled multifunctional photocatalysis behavior, including hydrogen production, degradation (Rhodamine B) and bactericidal (Escherichia coli) properties, which represented extraordinary sustainability. Finite-difference time-domain (FDTD) simulations manifested that the integration of double-layer hollow g-C 3 N 4 nanotubes with W 18 O 49 nanowires could expand the light harvesting ability. Demonstrated by density functional theory (DFT) calculations and electron spin resonance (ESR) measurements, the S-scheme heterojunction not only promoted the separation of carriers, but also improved the redox ability of the catalyst. This work provides a theoretical basis for enhancing the photocatalytic performances and broadening the application field of photocatalysis. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) are known for their versatile combination of inorganic building units and organic linkers, which offers immense opportunities in a wide range of applications. However, many MOFs are typically synthesized as multiphasic polycrystalline powders, which are challenging for studies by X‐ray diffraction. Therefore, developing new structural characterization techniques is highly desired in order to accelerate discoveries of new materials. Here, we report a high‐throughput approach for structural analysis of MOF nano‐ and sub‐microcrystals by three‐dimensional electron diffraction (3DED). A new zeolitic‐imidazolate framework (ZIF), denoted ZIF‐EC1, was first discovered in a trace amount during the study of a known ZIF‐CO3‐1 material by 3DED. The structures of both ZIFs were solved and refined using 3DED data. ZIF‐EC1 has a dense 3D framework structure, which is built by linking mono‐ and bi‐nuclear Zn clusters and 2‐methylimidazolates (mIm−). With a composition of Zn3(mIm)5(OH), ZIF‐EC1 exhibits high N and Zn densities. We show that the N‐doped carbon material derived from ZIF‐EC1 is a promising electrocatalyst for oxygen reduction reaction (ORR). The discovery of this new MOF and its conversion to an efficient electrocatalyst highlights the power of 3DED in developing new materials and their applications. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) are known for their versatile combination of inorganic building units and organic linkers, which offers immense opportunities in a wide range of applications. However, many MOFs are typically synthesized as multiphasic polycrystalline powders, which are challenging for studies by X‐ray diffraction. Therefore, developing new structural characterization techniques is highly desired in order to accelerate discoveries of new materials. Here, we report a high‐throughput approach for structural analysis of MOF nano‐ and sub‐microcrystals by three‐dimensional electron diffraction (3DED). A new zeolitic‐imidazolate framework (ZIF), denoted ZIF‐EC1, was first discovered in a trace amount during the study of a known ZIF‐CO3‐1 material by 3DED. The structures of both ZIFs were solved and refined using 3DED data. ZIF‐EC1 has a dense 3D framework structure, which is built by linking mono‐ and bi‐nuclear Zn clusters and 2‐methylimidazolates (mIm−). With a composition of Zn3(mIm)5(OH), ZIF‐EC1 exhibits high N and Zn densities. We show that the N‐doped carbon material derived from ZIF‐EC1 is a promising electrocatalyst for oxygen reduction reaction (ORR). The discovery of this new MOF and its conversion to an efficient electrocatalyst highlights the power of 3DED in developing new materials and their applications. [ABSTRACT FROM AUTHOR]