Hierarchical ZnS‐In₂S₃‐CuS Nanospheres with Nanoporous Structure: Facile Synthesis, Growth Mechanism, and Excellent Photocatalytic Activity

Abstract

The photocatalytic splitting of water is an attractive, environmentally friendly method that offers a way of capturing available solar energy and converting it into valuable hydrogen. [ 1 ] In the past few decades, although various efforts have been made to improve the photocatalytic activities of the photocatalysts, only a few effective photocatalysts for H 2 production under visible-light irradiation have been reported. [2][3][4][5][6][7] Therefore, it is desirable to seek novel visible-light photocatalysts with high effi ciency for energy conversion. In recent years, sulfi de solid solutions, such as ZnS-AgInS 2 , [ 8 ] ZnS-CuInS 2 , [ 9 ] and ZnSAgInS 2 -CuInS 2 , [ 10 ] have been extensively studied because of their controllable band structures and excellent performance for photocatalytic hydrogen production under visible light irradiation. However, a high-temperature heat treatment is needed for the preparation of these solid solutions and expensive noble metals need to be loaded on the surface as co-catalysts in order to improve their photocatalytic effi ciency.Porous inorganic materials have also received a great deal of interest because of their wide range of applications in the fi elds of catalysis, [ 11 , 12 ] solar cells, [ 13 ] supercapacitors, [ 14 ] and gas sensors. [ 15 ] For photocatalysts with a nanoporous structure e − /h + recombination in the bulk is reduced and, moreover, a quicker surface e − /h + separation, faster interfacial charge-carrier transfer, and better charge-carrier trapping are achieved. [ 16 ] Therefore, nanoporous photocatalysts are capable of exhibiting a high activity for H 2 evolution under visible-light irradiation. In our previous work, [ 17 ] hierarchically assembled porous ZnS-In 2 S 3 -Ag 2 S solid solutions showed relatively high activities for photocatalytic H 2 evolution under visible-light irradiation ( λ > 400 nm) even in the absence of co-catalysts. This result implies that the preparation of porous sulfi de solid solutions may provide a new pathway to designing and fabricating novel photocatalyst materials with high activities under visiblelight irradiation.The self-assembly of nanoparticles into three-dimensional (3D) hierarchical superstructures is a well-known route for fabricating porous materials. [ 18 , 19 ] Binary II-VI nanocrystals [20][21][22][23][24][25][26][27][28][29][30] and polynary chalcogenides [31][32][33][34][35][36] have been intensively studied owing to their unique structures and enhanced performances in various applications. However, very limited successes have been achieved on the fabrication of complex ZnS solid-solution hierarchitectures (hierarchical architectures) with a nanoporous structure. Therefore, the preparation of ZnS solid solutions with novel hierarchitectures is attractive because unique properties might be derived from their special morphologies. Moreover, it is important to explore the underlying mechanism by which the complex nanostructures are assembled from the primary species because a good understanding of the proc...

A Facile Route to Flowerlike Bi2S3 Constructed by Polycrystalline Nanoplates with Enhanced Electrochemical Properties

“…The XRD pattern of the sample synthesized at 100°C is shown in Figure 4a. Except the peaks corresponding to Bi 6 2-anions. The low-magnification FESEM image of the asprepared sample demonstrates that the final product consists of many microspheres assembled by many tiny nanoplates (Figure 4b).…”

“…When the reaction time was changed to 6 h, the small nanoparticles completely disappeared, and uniform flowerlike Bi 2 S 3 crystals were finally obtained (Figure 1b On the basis of the above results, we propose that a possible formation mechanism of the flowerlike Bi 2 S 3 consists of an anion exchange process and a self-assembly growth mechanism. In the early stage of the reaction, Bi(NO 3 ) 3 reacts with water to form Bi 6 2-anions through anion exchange. Thus, the Bi 2 S 3 nuclei form.…”

A Solution‐Processable Polymer Photocatalyst for Hydrogen Evolution from Water

“…[5] A large number of inorganic photocatalysts have been studied for hydrogen evolution. [6][7][8][9] By contrast, organic photocatalysts are much less explored, despite possible advantages such as tunable bandgaps, synthetic control over structure, good processability, and preparation from earth-abundant materials. [10,11] The most widely studied organic-derived photocatalysts for hydrogen evolution are the family of materials known as "graphitic carbon nitrides" (g-C 3 N 4 ).…”

Enhanced photocatalytic H2 evolution over CdS/Au/g-C3N4 composite photocatalyst under visible-light irradiation

“…[1][2][3][4][5] Since the pioneering work by Fujishima and Honda, 1 a large number of photocatalysts have been developed for water splitting. 3,[6][7][8][9][10][11][12][13][14] Among these photocatalysts, TiO 2 -based photocatalysts have been extensively studied on account of their high activity, long-term stability, and low cost. 15 Unfortunately, TiO 2 mainly harvests the ultraviolet (UV) light (about 4% of the solar energy), which restrains its utilization of the sunlight.…”