One-step chemical bath co-precipitation method to prepare high hydrogen-producing active ZnxCd1-xS solid solution with adjustable band structure

Lili Lu,Jun Pan,Rui Dong,Pengfei Tan,Yongjin Ma,Yi Chen

doi:10.1007/s10853-020-05668-2

Lili Lu, Jun Pan + Show 4 more

Open Access

https://doi.org/10.1007/s10853-020-05668-2

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Abstract

A series of ZnxCd1−xS solid solutions were synthesized through a simple one-step chemical bath co-precipitation route. The microstructure, morphology, composition and optical properties had been thoroughly investigated. The results showed that the as-obtained ZnxCd1−xS samples exhibited monodisperse spherical feature. These monodisperse ZnxCd1−xS spheres were composed of a large number of 5–10 nm crystal grains. The chemical composition of the ZnxCd1−xS solid solutions can be controlled by adjusting the ratio of Zn source to Cd source and the dosage of ammonia solution. Meanwhile, the energy band structure and photocatalytic properties can be optimized. The photocatalysis experiment results revealed that the as-synthesized Zn0.30Cd0.70S sample exhibited optimum water splitting performance. The satisfactory hydrogen evolution rate (HER) of Zn0.30Cd0.70S reached 27.004 mmol g−1 h−1 even without any cocatalysts, which was more than 48 times that of pure CdS (0.561 mmol g−1 h−1). This enhancing effect can owe to the balance between light absorption capacity and redox potential caused by the incorporation of Zn in the ZnxCd1−xS solid solutions.

Highlights

As human society is constantly evolving, energy crisis and environmental damage problems have become the two major issues that must be solved which is considered to be the most ideal approach to solving both environmental and energy problems [4,5,6,7]
Numerous potential semiconductor materials have been used in the practice of PEC water splitting, such as SrTiO3 [8,9,10], BaTiO3 [10, 11], ZnO [12, 13], CeO2 [14, 15], g-C3N4 [15,16,17,18], ZnS [19,20,21] and CdS [21,22,23,24]
As a typical semiconductor photocatalyst that can respond to visible light, CdS has a small band gap (Eg) and a favorable redox potential, which is suitable for photocatalytic water splitting [25]

Summary

Introduction

As human society is constantly evolving, energy crisis and environmental damage problems have become the two major issues that must be solved. For the consideration of scale production and practical application, this method has obvious advantages For this reason, we tried to synthesize the ZnxCd1-xS photocatalyst under a mild condition through a simple one-step chemical bath co-precipitation method. We successfully synthesized a series of ZnxCd1-xS solid solution materials via a simple chemical bath co-precipitation route without using any organic solvents or templates. These solid solutions obtained by inserting Zn ions into the CdS lattice inherit the advantages of the visible light response of CdS and the high reduction potential of ZnS and improve the problems of severe photocorrosion of CdS and the narrow light response range of ZnS. The applied voltage varies from - 1.5 V to 1.0 V

Results and discussion

Conclusions

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