Unique Layer-Doping-Induced Regulation of Charge Behavior in Metal-Free Carbon Nitride Photoanodes for Enhanced Performance

Peng Luan; Qingqiang Meng; Jing Wu; Qinye Li; Xiaolong Zhang; Ying Zhang; Luke A O'Dell; Sonia R Raga; Jennifer Pringle; James C Griffith; Chenghua Sun; Udo Bach; Jie Zhang

doi:10.1002/cssc.201902967

Unique Layer-Doping-Induced Regulation of Charge Behavior in Metal-Free Carbon Nitride Photoanodes for Enhanced Performance

ChemSusChem. 2020 Jan 19;13(2):328-333. doi: 10.1002/cssc.201902967. Epub 2019 Dec 13.

Authors

Peng Luan¹, Qingqiang Meng², Jing Wu³, Qinye Li⁴, Xiaolong Zhang¹, Ying Zhang¹, Luke A O'Dell⁵, Sonia R Raga⁴, Jennifer Pringle⁵, James C Griffith⁶, Chenghua Sun⁷, Udo Bach⁴, Jie Zhang¹

Affiliations

¹ School of Chemistry, Monash University, Clayton, VIC 3800, Australia.
² MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China.
³ State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150001, P. R. China.
⁴ Department of Chemical Engineering, Monash University, Clayton, VIC, 3800, Australia.
⁵ Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC, 3216, Australia.
⁶ Monash X-ray Platform, Monash University, Wellington Road, Clayton, VIC, 3800, Australia.
⁷ Department of Chemistry and Biotechnology and Center for Translational Atomaterials, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia.

PMID: 31777179
DOI: 10.1002/cssc.201902967

Abstract

Photoinduced charge carrier behavior is critical in determining photoelectrocatalytic activity. In this study, a unique layer-doped metal-free polymeric carbon nitride (C₃ N₄ ) photoanode is fabricated by using one-pot thermal vapor deposition. With this method, a photoanode consisting of a phosphorus-doped top layer, boron-doped middle layer, and pristine C₃ N₄ bottom layer, was formed as a result of the difference in thermal polymerization kinetics associated with the boron-containing H₃ BO₃ -melamine complex and the phosphorus-containing H₃ PO₄ -dicyandiamide complex. This layer-doping fabrication strategy effectively contributes to the formation of dual junctions that optimizing charge carrier behavior. The ternary-layer C₃ N₄ photoanode exhibits significantly enhanced photoelectrochemical water oxidation activity compared to pristine C₃ N₄ , with a record photocurrent density of 150±10 μA cm^-2 at 1.23 V vs. RHE. This layer-doping strategy provides an effective means for design and fabrication of photoelectrodes for solar water oxidation.

Keywords: carbon nitride; charge behavior; doping; photoelectrochemistry; water splitting.