Developing efficient piezocatalytic systems for two-electron water splitting (TEWS) with producing H 2 and H 2 O 2 shows great promise to meet the industrial demand. Herein, Ag single atoms (SAs) and clusters are co-anchored on carbon nitride (Ag SA + C À CN) to serve as the multifunctional sites for efficient TEWS. The Ag SAs enhance the in-plane piezoelectric polarization of CN that is intimately modulated by the atomic coordination induced charge redistribution, and Ag clusters afford strong interfacial electric field to remarkably promote the out-of-plane migration of piezoelectrons from CN. Moreover, Ag SA + C À CN yields a larger piezoresistive effect that elevates carrier mobility under strain. Consequently, a superior H 2 and H 2 O 2 evolution rate of 7.90 mmol g À 1 h À 1 and 5.84 mmol g À 1 h À 1 is delivered by Ag SA + C À CN, respectively, far exceeding that of the previously reported piezocatalysts. This work not only presents the SAs decoration as an available polarization enhancement strategy, but also sheds light on the superiority of multi-sites engineering in piezocatalysis.

Single-crystal dendritic ZnO nanostructures in appearance of macroscale in mass production have been synthesized via the vapor-phase transport method with Cu catalyst at 930°C. The hierarchical ZnO dendrites with a long central trunk and lots of multilevel branches are composed of well-oriented nanorods whose diameters range from 60to800nm. Gas sensors based on as-synthesized ZnO products exhibit high sensitivity and selectivity to H2S gas at room temperature through detecting various gases. The large modulation of the energy barrier of contact between nanorods in ZnO dendrites by H2S gas at room temperature might be the origin of the high sensitivity. The results demonstrate that the ZnO dendrites, with macroscopical appearance and properties of nanomaterials, are potential to develop effective and high performance gas sensors. Moreover, the detailed humidity characteristics of the sensor have also been investigated in the relative humidity range of 5%-97.6%.

Inferior contact interface and low charge transfer efficiency seriously restrict the performance of heterojunctions. Herein, chemically bonded α-Fe 2 O 3 / Bi 4 MO 8 Cl (M = Nb, Ta) dot-on-plate Z-scheme junctions with strong internal electric field are crafted by an in situ growth route. Experimental and theoretical results demonstrate that the internal electric field provides a powerful driving force for vectorial migration of photocharges between Bi 4 MO 8 Cl and α-Fe 2 O 3 , and the interfacial FeÀ O bond not only serves as an atomiclevel charge flow highway but also lowers the charge transfer energy barrier, thereby accelerating Z-scheme charge transfer and realizing effective spatial charge separation. Impressively, α-Fe 2 O 3 /Bi 4 MO 8 Cl manifests a significantly improved photocatalytic activity for selective oxidation of aromatic alcohols into aldehydes (Con. � 92 %, Sel. � 96 %), with a performance improvement of one to two orders of magnitude. This work presents atomic-level insight into interfacial charge flow steering.

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Hydrogen sulfide (HS), as a typical atmospheric pollutant, is neurotoxic and flammable even at a very low concentration. In this study, we design stable HS sensors based on ZnO-carbon nanofibers. Nanofibers with 30.34 wt% carbon are prepared by a facial electrospinning route followed by an annealing treatment. The resulting HS sensors show excellent selectivity and response compared to the pure ZnO nanofiber HS sensors, particularly the response in the range of 102-50 ppm of HS. Besides, they exhibited a nearly constant response of approximately 40-20 ppm of HS over 60 days. The superior performance of these HS sensors can be attributed to the protection of carbon, which ensures the high stability of ZnO, and oxygen vacancies that improve the response and selectivity of HS. The good performance of ZnO-carbon HS sensors suggests that composites with oxygen vacancies prepared by a facial electrospinning route may provide a new research strategy in the field of gas sensors, photocatalysts, and semiconductor devices.