One‐Step Solid‐Phase Synthesis of 2D Ultrathin CdS Nanosheets for Enhanced Visible‐Light Photocatalytic Hydrogen Evolution

Abstract

Photocatalysts with 2D ultrathin nanosheet structures are gradually attracting significant interest from researchers because of their excellent photoelectric and physicochemical properties. However, the efficient fabrication of 2D CdS nanosheets with high crystallinity and ultrathin thickness still faces huge challenges. In this work, 2D ultrathin CdS nanosheets are synthesized through a simple one‐step solid‐phase strategy using CdSO4 · 8/3H2O as precursors in the CH4N2S atmosphere. The 2D ultrathin CdS nanosheet obtained by calcining at 300 °C for 4 h shows superior photocatalytic activity: the photocatalytic rate of hydrogen generation reaches 149.67 μmol h−1, and the corresponding apparent quantum efficiency is 36.7% at 450 nm. The enhanced photocatalytic activity and excellent photocatalytic stability are realized through the high crystallinity and ultrathin 2D nanosheet structure of CdS, which provide a high surface‐to‐volume ratio and enriched active adsorption sites. The 2D ultrathin nanosheet structure prevents the surface sulfide ions from being oxidized because of the extremely short interface distances and photocatalytic carrier transport, resulting in effective photocorrosion inhibition. Controlled experiments also show that the precursors ZnSO4 · 7H2O and Cd(Ac)2 · 2H2O are converted to 2D ZnS and CdS nanosheets through the one‐step solid‐phase method, illustrating that this simple one‐step solid‐phase strategy can be extended to the fabrication of other metal sulfide photocatalysts with 2D nanostructures.

Construction of an Ultrathin S‐Scheme Heterojunction Based on Few‐Layer g‐C3N4 and Monolayer Ti3C2Tx MXene for Photocatalytic CO2 Reduction

“…Transient photocurrent response (TPR) and electrochemical impedance spectra (EIS) were measured on an electrochemical workstation CHI660E using a standard three‐electrode system. [ 63,64 ] During the testing of TPR, three electrodes consisting of a working electrode (samples), a reference electrode (KCl‐saturated Ag/AgCl), and a counter electrode (Pt wire) were immersed in 0.5 m Na 2 SO 4 solution. Then, a 300 W Xe lamp, which was used as a visible‐light source of the working electrode, was turned on and off in sequence every 60 s to record the current change.…”

Structural engineering of 3D hierarchical Cd0.8Zn0.2S for selective photocatalytic CO2 reduction

“…Thus, the fabrication of photocatalysts with sufficient CO2 adsorption and charge-transfer capabilities is needed [15][16][17][18]. So far, a relatively new effort of designing desirable morphologies and architectures benefits solar-harvesting and CO2 absorption, leading to increased active sites and potential interface functionalities [19,20]. For instance, Liu et al [21] prepared ultrathin 2D covalent organic framework nanosheets with excellent CO production due to a large surface area and enhanced contact between the substrate and the molecule.…”

Carbon–Graphitic Carbon Nitride Hybrids for Heterogeneous Photocatalysis

“…Generally, perfectly constructed photocatalysts for remarkable photocatalytic performance are indispensably provided with sufficient light absorption (form UV to visible light), great charge carriers yielding, and high electrical conductivity. [ 23,74–76 ] As a highly aligned carbon/nitrogen composition with tri‐ s ‐triazines interrelated via tertiary amines, g‐C 3 N 4 has appropriate band positions (conduction band (CB) at ≈−1.1 eV and valence band (VB) at ≈+1.6 eV vs normal hydrogen electrode (NHE) at pH = 0). [ 17,62 ] The moderate chemical potential enables g‐C 3 N 4 with redox abilities in various photocatalytic reactions under visible light irradiation.…”