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A novel photochemical and electrochemical co-regulation strategy for fabricating BiVO4 photoanodes was developed, and an excellent photocurrent density of 6.42 mA cm−2 can be delivered with the assistance of an ultrathin NiFeOx layer at 1.23 V versus RHE.

Cu5FeS4 quantum dots as a single-component photo-assisted electrocatalyst for efficient hydrogen evolution reaction superior to Pt/C.

Electrochemical nitrogen reduction reaction (NRR) is considered as one of the most promising methods for NH₃ synthesis under room temperature and ambient pressure. A grand challenge of NRR is the development of efficient electrocatalysts, for which the delicate nanostructuring of catalysts plays an important role. Herein, a series of Fe-doped Cu₂–ₓS quantum dots (QDs) are synthesized with multiple active sites and interface engineering, in which the double-phase heterostructure plays a key role for boosting NRR activity. The yield of NH₃ was obviously improved with the increase of Fe content from 0 to 3% but started to decrease with Fe from 3 to 9%. The optimized Fe₃%–Cu₂–ₓS QDs show an outstanding NH₃ yield of 26.4 μg h–¹ mg–¹cₐₜ at −0.7 V (vs the reversible hydrogen electrode), which is 5 times higher than that of Cu₂–ₓS QDs. More importantly, we observed that the highest NRR activity in Fe₃%–Cu₂–ₓS QDs was ascribed to the formation of an inherent double-phase heterostructure of Cu₂–ₓS/Cu₅FeS₄, whereas the complete conversion to single-phase Cu₅FeS₄ with increased Fe doping (9%) resulted in the activity decrease. Further, N₂ temperature-programmed desorption and electrochemical impedance spectra characterizations confirm the stronger chemical adsorption of N₂ and faster charge transfer in the Cu₂–ₓS/Cu₅FeS₄ QDs. A plausible mechanism was proposed for the double-phase Cu₂–ₓS/Cu₅FeS₄ heterostructure, where the interface provides efficient charge transfer and more active sites of Cu, Fe, and S for the synergetic adsorption and activation of N₂. Our work provides a simple strategy for the design of NRR electrocatalysts, which may also bring new inspiration for the preparation of the inherent double-phase heterostructure within other doped QDs.

Semiconductor quantum dots (QDs) have shown excellent advantages in photocatalysis owing to the unique optical properties, adjustable bandgap and high specific surface area. However, the small size...

Zinc bromine redox flow battery (ZBFB) has been paid attention since it has been considered as an important part of new energy storage technology. This paper introduces the working principle and main components of zinc bromine flow battery, makes analysis on their technical features and the development process of zinc bromine battery was reviewed, and emphasizes on the three main components of zinc bromine battery, and summarizes the materials and applications of electrolyte, membrane and electrode. At the same time, the solution to the technical problems of zinc bromine flow battery is also briefly analyzed. Finally, the future development of zinc bromine battery system is prospected.

Electrocatalytic nitrogen reduction reaction (NRR) has been considered as an efficient and environment-friendly alternative method for NH3 production. However, the balance between selectivity and catalytic activity is still one of the biggest challenges for developing efficient electrocatalysts. Here, we propose a simple method for the preparation of Cu2-xS/MoS2 electrocatalysts via epitaxial growth of an ultra-thin MoS2 layer on monodispersed Cu2-xS quantum dots. The highest NH3 yield of 22.1 µg h-1 mgcat.-1 and Faraday efficiency of 6.06% were obtained at -0.5 V (versus reversible hydrogen electrode) on Cu2-xS/MoS2-2.5% with an ultrathin MoS2 shell (~1 nm). But it started to decrease with further Mo/Cu ratio increase to 5% and 10%, due to the competition of hydrogen evolution and subsequent reduction of the Faraday efficiency. Further mechanism studies demonstrate that the delicate core/shell structure regulation with an ultrathin MoS2 shell can enhance the nitrogen adsorption capacity, electrochemical active surface area, and charge transfer rate. A plausible mechanism was proposed for NRR on the Cu2-xS/MoS2 core/shell catalysts, where the controllable ultrathin MoS2 layer can effectively increase the NRR performance at the interface while avoiding the unwanted enhancement of hydrogen evolution. This work provides a paradigm for enhancing activity and selectivity through rational core/shell nanostructure engineering for the design of NRR electrocatalysts.

Intracellular ions played prominent part in cell function and behavior. Disrupting intracellular ions homeostasis might switch ions signal from "regulating" to "destroying". Inspired by this, we introduced the ions interference strategy for tumor therapy. Herein, curcumin (CUR) and transferrin (Tf) co-loaded calcium peroxide nanoparticles (CaO2 NPs) were formulated. With tumor targeting ability, CaO2/Tf/CUR pinpointed tumor cells and then instantaneously decomposed in acidic lysosomes, concurrently accompanying with the release of Ca2+ and CUR, as well as the production of H2O2. Then H2O2 not only damaged structure of Tf to release Fe3+, but also was converted to hydroxyl radicals via ferric ions mediated Fenton reaction for ferroptosis. In addition, the released Ca2+ and CUR induced Ca2+ overload via exogenous and endogenous calcium ions accumulation, respectively, further activating mitochondria apoptosis signaling pathway for cell injury. Therefore, based on calcium and ferric ions interference strategy, the cascade catalytic CaO2/Tf/CUR offered synergistic combination of ferroptosis, Ca2+ overload therapy and chemotherapy, which held a great promise in cancer treatment.

The electrocatalytic water splitting to hydrogen and oxygen plays a critical role on renewable energy conversion and storage, which relies heavily on the development of high-efficiency, low-cost and robust catalysts. Here, employing the industrial 316 L stainless steel (SS), the hydrogen evolution reaction (HER) performance of a series of SS meshes with different mesh number (100–1600) were studied in acidic condition. The results exhibit that the cheap industrial 316 L SS meshes have excellent electrocatalytic HER activity. Meanwhile, the electrocatalytic HER performance of the 316 L SS meshes increases with the increase of mesh number. The HER activity was increased with the mesh number increases from 100 to 1600 meshes, where the optimized 316 L SS-1600 obtains a low overpotential of 209.8 mV at the current density of 10 mA cm−2 and a small Tafel slope (115.6 mV dec−1). However, with further increase of the mesh number from 1600 meshes to 2800 meshes, the HER performance started to decrease. A possible mechanism for the effect of the mesh number on HER performance was proposed, which can be ascribed to the electrochemical specific surface area and the tight interweaving of SS mesh for hydrogen release. This work provides an important direction for the performance improvement of the low-cost industrially available electrodes towards scale-up electrocatalytic hydrogen production and renewable energy storage.

Multinary sulfide quantum dots (QDs) have exhibited outstanding advantages including large surface areas, unique optical properties and adjustable band gap, which are beneficial for visible-active photocatalysis. However, the use of QDs also brings about serious issues of charge recombination and particle agglomeration. Here, a rational design of direct 0D/2D Z-scheme heterojunction of Zn-AgIn5S8/α-Fe2O3 is described. Appropriate band alignment is conducive to the construction of Z-scheme heterostructures, thus enhancing the redox ability of the semiconductors and inhibiting the charge recombination. Simultaneously, the zeta potential differences between the two semiconductors can make them achieve a close interface contact by electrostatic adsorption and then the 0D Zn-AgIn5S8 (ZAIS) QDs can be dispersed uniformly on 2D α-Fe2O3 nanosheets, which can reduce the agglomeration of QDs. At the same time, the advantages of large specific surface area and short electron transmission path of QDs can also be exerted. Meanwhile, α-Fe2O3 nanosheets with high conductivity can rapidly lead out the photogenerated charge carriers and thus suppress the recombination of the electrons and holes in QDs. The optimum nanocomposites with 3 wt% α-Fe2O3 nanosheets display a photocatalytic H2 evolution rate of 1.7 mmol g−1 h−1, 3.5 times to that of pure QDs, with an apparent quantum efficiency of 7.48% at 450 nm. Electrochemiluminescence spectra, time-resolved photoluminescence spectra and electron spin resonance spectra further testify the enhanced charge transfer and the direct Z-scheme mechanism of the 0D/2D heterojunction. This work emphasizes the suitable band matching to adjust the exciton properties and charge transfer characteristics of QDs by constructing Z-scheme heterojunction for efficient utilization of visible light.

Air pollution in transportation cabins has recently become a public concern. However, few studies assessed the exposure levels of suspected air pollutants including Volatile Organic Compounds (VOCs). This paper studied the exposure levels of in-carriage VOCs (benzene, toluene, ethylbenzene, xylene, styrene, formaldehyde, acetaldehyde, acetone and acrolein) in Shanghai, China and estimated the health risk in different conditions. The results indicated that VOCs concentrations in metro carriages varied from different train models, due to the difference in carriage size and ventilation system. The concentrations of aromatic VOCs in old metro carriage were 1-2 times higher than the new ones, as better paintings were used in new trains. Poor air circulation and ventilation in the underground track was likely to be the cause of higher VOCs levels (~10%) than the above-ground track. Lower aromatic compounds levels and higher carbonyls levels were observed in metro carriages at suburban areas than those at urban areas, likely due to less aromatic emission sources and more carbonyls emission sources in suburban areas. Acetone and acrolein were found to increase from 7.71 to 26.28μg/m3 with number of commuters increasing from 40 to 200 in the carriages. According to the acceptable level proposed by the World Health Organization (1×10-6-1×10-5), the life carcinogenic risk of commuters by subway (8.5×10-6-4.8×10-5) was little above the acceptable level in Shanghai. Further application of our findings is possible to act as a reference in facilitating regulations for metro systems in other cities around world, so that in-carriage air quality might be improved.