Electrochemical water splitting is a clean technology for H2 fuels, but greatly hindered by the slow kinetics of the oxygen evolution reaction (OER). Herein, a series of spinel-structured nanosheets with oxygen deficiencies and ultrathin thicknesses were designed to increase the reactivity and the number of active sites of the catalysts, which were then taken as an excellent platform for promoting the water oxidation process. Theoretical investigations showed that the oxygen vacancies confined in the ultrathin nanosheet could lower the adsorption energy of H2O, leading to increased OER efficiency. As expected, the NiCo2O4 ultrathin nanosheets rich in oxygen vacancies exhibited a large current density of 285 mA cm(-2) at 0.8 V and a small overpotential of 0.32 V, both of which are superior to the corresponding values of bulk samples or samples with few oxygen deficiencies and even higher than those of most reported non-precious-metal catalysts. This work should provide a new pathway for the design of advanced OER catalysts.

7373wileyonlinelibrary.com communication, wide spectral switches or memory storage through the use of single detector. During the light communication, in order to improve the transmission rate and increase the transmission capacity, the wide spectrum photodetection is necessary. In the case of ultraviolet-visible light communication, the photodetectors can be used in the sunlight and other illumination light which is in our daily lives. By utilizing the harmless characteristics of entire visible light, the visible photodetector is expected to be a promising candidate of high-power infrastructure for indoor/outdoor public ubiquitous data communication technology in the near future. So far, studies about photodetectors were mainly focused on their performances under special wavelength, due to the lack of proper materials which have the ability to absorb of incident radiation over broad wavelength range with excellent optoelectronic transfer effi ciency. To expand the wavelength range of operation and obtain the enhanced properties, efforts have been devoted to design the photodetectors with wide spectral sensitivity through the combination of several different functional materials, which undergoes complicated fabrication process and requires expensive equipment (chemical vapor deposition, thermal evaporation, and so on), thus drawing back their applications. For example, the carbon nanotube/TiO 2 core-shell nanowires with broadband lightharvesting ability were grown through the atomic layer deposition (ALD) method by controlling the TiCl 4 /H 2 O fl ow rate at 0.25 Å/cycles after preheated carbon nanotube in the ALD reactor chamber. [ 5 ] The expensive equipment and complicated fabrication processes will undoubtedly restrict their extensive applications. Thus, searching for proper materials with wide spectral sensitivity and easy assembly is urgently needed in the area of photodetectors.Bearing this in mind, we paid our attention to the hybrid organolead halide perovskites with a general formula of (RNH 3 ) MX 3 (R = C n H 2n+1 ; X = halogen I, Br, Cl; M = Pb, Cd, Sn and so on), which have attracted signifi cant interests in electronic and photonic applications recently, [6][7][8][9][10][11] owing to their appropriate direct bandgap, [ 12 ] large absorption coeffi cient, [ 13 ] long range balanced electron and hole-transport lengths, [ 14,15 ] high electrical mobility, [ 16,17 ] and so on. Furthermore, the series of (RNH 3 )MX 3 perovskites can be fabricated by a simple and costeffective solution-based self-assembly method, rendering the (RNH 3 )MX 3 to be a competitive candidate for the application Organolead halide perovskites have attracted extensive attentions as light harvesting materials for solar cells recently, because of its high chargecarrier mobilities, high photoconversion effi ciencies, low energy cost, ease of deposition, and so on. Herein, with CH 3 NH 3 PbI 3 fi lm deposited on fl exible ITO coated substrate, the fi rst organolead halide perovskite based broadband photodetector is demonstrated. The ...

Limited by the relatively sluggish charge-carrier separation in semiconductors, the photocatalytic performance is still far below what is expected. Herein, a model of ZnIn2 S4 (ZIS) nanosheets with oxygen doping is put forward to obtain in-depth understanding of the role that doping atoms play in photocatalysis. It shows enhanced photocatalytic activity compared with pristine ZIS. The electron dynamics analyzed by ultrafast transient absorption spectroscopy reveals that the average recovery lifetime of photoexcited electrons is increased by 1.53 times upon oxygen incorporation into the ZIS crystals, indicating enhanced separation of photoexcited carriers in oxygen-doped ZIS nanosheets. As expected, the oxygen-doped ZIS nanosheets show a remarkably improved photocatalytic activity with a hydrogen evolution rate of up to 2120 μmol h(-1)  g(-1) under visible-light irradiation, which is 4.5 times higher than that of the pristine ZIS nanosheets.