Article

A suspension-mimicking hydrogel-based n-type polymer photocathode for solar-driven water splitting

Wenwen ZhaJiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 21189, PR ChinaQiushi RuanJiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 21189, PR ChinaLingqiao KongJiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 21189, PR ChinaXufeng XiJiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 21189, PR ChinaMuhammad Ali TurgunovDepartment of Mechanical and Aerospace Engineering, Turin Polytechnic University, Tashkent 100095, UzbekistanWei ZhangJiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 21189, PR ChinaKun ChangCollege of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, PR ChinaZhengMing SunJiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 21189, PR China

Cell Reports Physical Sciencejournal2022en

ABI

Abstract

Graphitic carbon nitride is a benchmark n-type polymer photocatalyst for hydrogen evolution from water in suspension systems, though it is extremely inefficient in photoelectrochemical (PEC) systems. Minimizing the considerable discrepancy between the two systems is challenging but necessary for applications. Efficient electron collection on the catalyst surface is key to carbon nitride’s photocatalytic hydrogen evolution performance in suspension systems, but it is rarely achieved in PEC films because of the electron transfer barrier from bulk to the surface. Here, we report a hydrogel-based PEC photocathode that inherits the intrinsic advantages of suspension systems, providing a suspension-like environment for carbon nitride hydrogen evolution. This promotes electron trapping at heteroatom-induced shallow surface trap states, mitigates space charge layer, and reduces charge migration distance in hydrogel-supported heteroatoms-doped carbon nitride nanosheets, enabling efficient electron collection on the surface, leading to 10-time improvement in photocathodic performance. This study provides proof of concept for mimicking suspension in photoelectrodes that can be applied to various powder-based photoelectrochemical cells.

Topics

Electrowetting and Microfluidic Technologies TiO2 Photocatalysis and Solar Cells Analytical Chemistry and Sensors

Identifiers

DOI: 10.1016/j.xcrp.2022.100863

Citations and references

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