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Tandem catalysts can divide the reaction into distinct steps by local multiple sites and thus are attractive to trigger CO2RR to C2+ products. However, the evolution of catalysts generally exists during CO2RR, thus a closer investigation of the reconstitution, interplay, and active origin of dual components in tandem catalysts is warranted. Here, taking AgI−CuO as a conceptual tandem catalyst, we uncovered the interaction of two phases during the electrochemical reconstruction. Multiple operando techniques unraveled that in situ iodine ions leaching from AgI restrained the entire reduction of CuO to acquire stable active Cu0/Cu+ species during the CO2RR. This way, the residual iodine species of the Ag matrix accelerated CO generation and iodine‐induced Cu0/Cu+ promotes C−C coupling. This self‐adaptive dual‐optimization endowed our catalysts with an excellent C2+ Faradaic efficiency of 68.9 %. Material operando changes in this work offer a new approach for manipulating active species towards enhancing C2+ products. [ABSTRACT FROM AUTHOR]

Metal oxides are archetypal CO2 reduction reaction electrocatalysts, yet inevitable self-reduction will enhance competitive hydrogen evolution and lower the CO2 electroreduction selectivity. Herein, we propose a tangible superlattice model of alternating metal oxides and selenide sublayers in which electrons are rapidly exported through the conductive metal selenide layer to protect the active oxide layer from self-reduction. Taking BiCuSeO superlattices as a proof-of-concept, a comprehensive characterization reveals that the active [Bi2O2]2+ sublayers retain oxidation states rather than their self-reduced Bi metal during CO2 electroreduction because of the rapid electron transfer through the conductive [Cu2Se2]2- sublayer. Theoretical calculations uncover the high activity over [Bi2O2]2+ sublayers due to the overlaps between the Bi p orbitals and O p orbitals in the OCHO* intermediate, thus achieving over 90% formate selectivity in a wide potential range from −0.4 to −1.1 V. This work broadens the studying and improving of the CO2 electroreduction properties of metal oxide systems. It is important yet challenging to improve the interface contact between commonly used carbon conductive layer and metal oxide catalysts. Here the authors propose BiCuSeO with alternant active [Bi2O2]2+ sublayers and conductive [Cu2Se2]2- sublayer within its superlattice as efficient catalyst for CO2 electroreduction to formate. [ABSTRACT FROM AUTHOR]

Bimetallic sulfides are expected to realize efficient CO2 electroreduction into formate over a wide potential window, however, they will undergo in situ structural evolution under the reaction conditions. Therefore, clarifying the structural evolution process, the real active site and the catalytic mechanism is significant. Here, taking Cu2SnS3 as an example, we unveiled that Cu2SnS3 occurred self‐adapted phase separation toward forming the stable SnO2@CuS and SnO2@Cu2O heterojunction during the electrochemical process. Calculations illustrated that the strongly coupled interfaces as real active sites driven the electron self‐flow from Sn4+ to Cu+, thereby promoting the delocalized Sn sites to combine HCOO* with H*. Cu2SnS3 nanosheets achieve over 83.4 % formate selectivity in a wide potential range from −0.6 V to −1.1 V. Our findings provide insight into the structural evolution process and performance‐enhanced origin of ternary sulfides under the CO2 electroreduction. [ABSTRACT FROM AUTHOR]

Development of efficient photocatalysts for hydrogen (H2) production from water splitting is highly sought for the current sustainable energy issue. This paper has demonstrated a one-pot hydrothermal approach for the preparation of hierarchical nanostructures (HNs) composed only of Nb3O7F single-crystalline nanorods by using H2NbF7 as a precursor and 2-propanol as a selective adsorption agent. In our protocol, modulating the hydrolysis rate of the coordination complex H2NbF7via simply controlling its concentration not only produces Nb3O7F single crystalline nanorods by the restrictive growth on [110] due to the selective adsorption of 2-propanol on the sidewalls, but also leads to secondary nucleation for the growth of new nanorods on the pre-formed ones, leading to the formation of Nb3O7F HNs. The resultant Nb3O7F HNs strongly respond to ultraviolet light and have a band gap of 3.22 eV as well as the conducting band minimum at −0.44 eV. They exhibit excellent photocatalytic H2 production activity with a good recycling stability when 0.5 wt% Pt is used as a cocatalyst. The H2 production rate reaches 830 µmol h−1 g−1, about 23.7 and 5.7 times higher than that of Nb2O5 sphere-shaped micro-particles and commercial Nb2O5 nanoparticles, respectively. Furthermore, they can also show notable photocatalytic H2 production activity even without any cocatalysts. This suggests that the resultant Nb3O7F HNs are promising as a new photocatalyst for H2 production. [ABSTRACT FROM AUTHOR]

Fluorinated Ta2O5 nanostructures are synthesized by hydrothermal reaction of Ta powder, 0.133 M aq. [ABSTRACT FROM AUTHOR]

Manipulating the catalyst-electrolyte interface to push reactants into the inner Helmholtz plane (IHP) is highly desirable for efficient electrocatalysts, however, it has rarely been implemented due to the elusive electrochemical IHP and inherent inert catalyst surface. Here, we propose the introduction of local force fields by the surface hydroxyl group to engineer the electrochemical microenvironment and enhance alkaline hydrogen evolution activity. Taking a hydroxyl group immobilized Ni/Ni 3 C heterostructure as a prototype, we reveal that the local hydrogen bond induced by the surface hydroxyl group drags 4-coordinated hydrogen-bonded H 2 O molecules across the IHP to become free H 2 O and thus continuously supply reactants forcatalytic sites catalytic sites. In addition, the hydroxyl group coupled with the Ni/Ni 3 C heterostructure further lowers the water dissociation energy by polarization effects. As a direct outcome, hydroxyl-rich catalysts surpass Pt/C activity at high current density (500 mA cm -2 @ ≈276 mV) in alkaline medium., (© 2022 Wiley-VCH GmbH.)

Tandem catalysts can divide the reaction into distinct steps by local multiple sites and thus are attractive to trigger CO 2 RR to C 2+ products. However, the evolution of catalysts generally exists during CO 2 RR, thus a closer investigation of the reconstitution, interplay, and active origin of dual components in tandem catalysts is warranted. Here, taking AgI-CuO as a conceptual tandem catalyst, we uncovered the interaction of two phases during the electrochemical reconstruction. Multiple operando techniques unraveled that in situ iodine ions leaching from AgI restrained the entire reduction of CuO to acquire stable active Cu 0 /Cu + species during the CO 2 RR. This way, the residual iodine species of the Ag matrix accelerated CO generation and iodine-induced Cu 0 /Cu + promotes C-C coupling. This self-adaptive dual-optimization endowed our catalysts with an excellent C 2+ Faradaic efficiency of 68.9 %. Material operando changes in this work offer a new approach for manipulating active species towards enhancing C 2+ products., (© 2022 Wiley-VCH GmbH.)

Bimetallic sulfides are expected to realize efficient CO 2 electroreduction into formate over a wide potential window, however, they will undergo in situ structural evolution under the reaction conditions. Therefore, clarifying the structural evolution process, the real active site and the catalytic mechanism is significant. Here, taking Cu 2 SnS 3 as an example, we unveiled that Cu 2 SnS 3 occurred self-adapted phase separation toward forming the stable SnO 2 @CuS and SnO 2 @Cu 2 O heterojunction during the electrochemical process. Calculations illustrated that the strongly coupled interfaces as real active sites driven the electron self-flow from Sn 4+ to Cu + , thereby promoting the delocalized Sn sites to combine HCOO* with H*. Cu 2 SnS 3 nanosheets achieve over 83.4 % formate selectivity in a wide potential range from -0.6 V to -1.1 V. Our findings provide insight into the structural evolution process and performance-enhanced origin of ternary sulfides under the CO 2 electroreduction., (© 2021 Wiley-VCH GmbH.)

The homemade explosive, triacetone triperoxide (TATP), is easy to synthesize, sensitive to detonation but hard to detect directly. Vapor sensor arrays composed of a few sensor materials have the potential to discriminate TATP, but the stability of the sensor array is always a tricky problem since each sensor may encounter a device fault. Thus, a sensor array based on a single optoelectronic TiO₂/PW 11 sensor was first constructed by regulating the excitation wavelength to discriminate TATP from other explosives. By in situ doping of Na₃PW 12 O 40 , a Keggin structure of PW 11 formed on the TiO₂ to promote the photoinduced electron-hole separation, thus obviously improving the detection sensitivity of the sensor film and shortening the response time. The response of the TiO₂/PW 11 sensor film to TATP under 365, 450 and 550 nm illumination is 81%, 42%, and 37%, respectively. The TiO₂/PW 11 sensor features selectivity to TATP and is able to detect less than 50 ppb. The flexibility and stability of the flexible sensor film is also demonstrated with the extent of bending. Furthermore, the sensing response cannot be affected by ambient air below 60% relative humidity., Competing Interests: The authors declare no conflicts of interest.