Highly Efficient Photocatalyst Based on a CdS Quantum Dots/ZnO Nanosheets 0D/2D Heterojunction for Hydrogen Evolution from Water Splitting

• DOI: 10.1021/acsami.7b08407
• Publication Date: 2017-07-11T16:26:55Z
• Authors: Dandan Ma; Jian-Wen Shi; Yajun Zou; Zhaoyang Fan; Xin Ji; Chunming Niu
• Keywords: Chemical bath deposition

A novel CdS/ZnO heterojunction constructed of zero-dimensional (0D) CdS quantum dots (QDs) and two-dimensional (2D) ZnO nanosheets (NSs) was rationally designed for the first time. The 2D NSs were assembled into microflowers (MFs) via an ultrasonic-assisted hydrothermal procedure (100 °C, 12 h) in presence a NaOH solution (0.06 M), QDs deposited on both sides every NS situ by using successive ionic-layer absorption reaction method. It found that ultrasonic treatment played important role generation NSs, while responsible to assembly flower-like structure. obtained 0D/2D heterostructures exhibited remarkably enhanced photocatalytic activity hydrogen evolution from water splitting comparison with other different dimensional combinations such as 2D/2D, 0D/three-dimensional (3D), 3D/0D. Among them, CdS/ZnO-12 (12 deposition cycles QDs) highest rate 22.12 mmol/g/h, which 13 138 times higher than those single (1.68 mmol/g/h) (0.16 mmol/g/h), respectively. can be attributed several positive factors, formation Z-scheme system, tiny size effect 0D intimate contact between NSs. system promoted separation migration photogenerated electron–hole pairs. effectively decreased recombination probability electrons holes. two semiconductors efficiently reduced resistance carriers. Furthermore, also presented excellent stability without any decay within five 25 h.