Flower-Like Dual-Defective Z-Scheme Heterojunction g-C3N4/ZnIn2S4 High-Efficiency Photocatalytic Hydrogen Evolution and Degradation of Mixed Pollutants.

Linlin Hou,Yasi Chen,Qiuming Wei,Teng Wang,Zhiliang Wu,Wei Li,Chun Jin

doi:10.3390/nano11102483

Linlin Hou, Yasi Chen + Show 5 more

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https://doi.org/10.3390/nano11102483

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Abstract

Graphitic carbon nitride (g-C3N4) with a porous nano-structure, nitrogen vacancies, and oxygen-doping was prepared by the calcination method. Then, it was combined with ZnIn2S4 nanosheets containing zinc vacancies to construct a three-dimensional (3D) flower-like Z-scheme heterojunction (pCN-N/ZIS-Z), which was used for photocatalytic hydrogen evolution and the degradation of mixed pollutants. The constructed Z-scheme heterojunction improved the efficiency of photogenerated charges separation and migration, and the large surface area and porous characteristics provided more active sites. Doping and defect engineering can change the bandgap structure to improve the utilization of visible light, and can also capture photogenerated electrons to inhibit recombination, so as to promote the use of photogenerated electron-hole pairs in the photocatalytic redox process. Heterojunction and defect engineering synergized to form a continuous and efficient conductive operation framework, which achieves the hydrogen production of pCN-N/ZIS-Z (9189.8 µmol·h−1·g−1) at 58.9 times that of g-C3N4 (155.9 µmol·h−1·g−1), and the degradation rates of methyl orange and metronidazole in the mixed solution were 98.7% and 92.5%, respectively. Our research provides potential ideas for constructing a green and environmentally friendly Z-scheme heterojunction catalyst based on defect engineering to address the energy crisis and environmental restoration.

Highlights

Energy and the environment have been important issues in the history of human development
On the premise of ensuring degradation efficiency, we found that the maximum concentration of the pCN-N/ZnIn2 S4 with zinc vacancies (ZIS-Z) degradation mixture is methyl orange (MO) (3 mg/L)/MNZ (30 mg/L)
It was not difficult to find that ZIS-Z shows a favorable visible-light absorption ability, because the zinc vacancies change the bandgap and expand the visible light absorption range

Summary

Introduction

Energy and the environment have been important issues in the history of human development. Many studies have reported that hydrogen is precipitated by electrolysis of water, but this method is energy-intensive and costly and is not conducive to mass production. Exploring low-cost, simple and environmentally friendly methods to produce hydrogen has become an important research topic [1,2]. With the progress of human society and the development of the industrial age, the use of antibiotics has increased due to the emergence of a variety of new diseases, and the entry of antibiotics into water will pose risks to human health and ecosystems [3,4,5,6,7].

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