Affiliation:
1. School of Physical Science and Technology Jiangsu Key Laboratory of Thin Films Center for Energy Conversion Materials & Physics (CECMP) Soochow University Suzhou 215006 P. R. China
2. College of Chemistry and Chemical Engineering Inner Mongolia University Hohhot 010021 P. R. China
3. School of Electronic and Information Engineering Changshu Institute of Technology Changshu 215500 P. R. China
4. Jiangsu Key Laboratory of Advanced Negative Carbon Technologies Soochow University Suzhou 215006 P. R. China
Abstract
AbstractHeteroatom doping can tune the band structure of semiconductors and enhance their carrier transfer capacity for improving the performance of photoelectrochemical water oxidation. Nevertheless, the introduction of dopants is not always beneficial. In this study, magnesium (Mg) is adopted to dope ZnIn2S4 nanosheet array photoanodes to form a type‐II band structure and reduce bulk recombination, but concurrently introduced deleterious oxygen (O) defects slow down the surface catalytic reaction kinetics. Furthermore, a facile heat treatment strategy is proposed to transform these O defects into Mg─O bonds. First‐principles calculations and electrochemical characterization indicate that the presence of Mg─O bonds provides abundant active sites and efficiently accelerates the surface oxygen evolution reaction by precisely realigning the rate‐determining step from OH* to O* (step 2) to OOH* to O2 (step 4), thereby retarding charge trapping and recombination. As a result, such a photoanode achieves a remarkable performance with a photocurrent as high as 4.91 mA cm−2 at 1.23 V versus reversible hydrogen electrode, and the onset potential shifts negatively about 340 mV. This work provides a new defect modulation idea for converting detrimental defects to favorable ones, and it can be expected to have wide applications in the fields of energy, catalysis, and optoelectronics, etc.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Subject
General Materials Science,Renewable Energy, Sustainability and the Environment