Enhancing the photocatalytic activity of bulk g-C₃N₄ by introducing mesoporous structure and hybridizing with graphene

Yuhan Li; Yanjuan Sun; Fan Dong; Wing-Kei Ho

doi:10.1016/j.jcis.2014.09.004

Enhancing the photocatalytic activity of bulk g-C₃N₄ by introducing mesoporous structure and hybridizing with graphene

J Colloid Interface Sci. 2014 Dec 15:436:29-36. doi: 10.1016/j.jcis.2014.09.004. Epub 2014 Sep 16.

Authors

Yuhan Li¹, Yanjuan Sun², Fan Dong³, Wing-Kei Ho⁴

Affiliations

¹ Chongqing Key Laboratory of Catalysis and Functional Organic Molecules, College of Environmental and Biological Engineering, Chongqing Technology and Business University, China; Department of Science and Environmental Studies, The Centre for Education in Environmental Sustainability, The Hong Kong Institute of Education, Hong Kong.
² Chongqing Key Laboratory of Catalysis and Functional Organic Molecules, College of Environmental and Biological Engineering, Chongqing Technology and Business University, China.
³ Chongqing Key Laboratory of Catalysis and Functional Organic Molecules, College of Environmental and Biological Engineering, Chongqing Technology and Business University, China. Electronic address: dfctbu@126.com.
⁴ Department of Science and Environmental Studies, The Centre for Education in Environmental Sustainability, The Hong Kong Institute of Education, Hong Kong. Electronic address: keithho@ied.edu.hk.

PMID: 25265582
DOI: 10.1016/j.jcis.2014.09.004

Abstract

Bulk graphitic carbon nitride (CN) suffers from small surface area and high recombination of charge carriers, which result in low photocatalytic activity. To enhance the activity of g-C3N4, the surface area should be enlarged and charge carrier separation should be promoted. In this work, a combined strategy was employed to dramatically enhance the activity of bulk g-C3N4 by simultaneously introducing mesoporous structure and hybridizing with graphene/graphene oxide. The mesoporous g-C3N4/graphene (MCN-G) and mesoporous g-C3N4/graphene oxide (MCN-GO) nanocomposites with enhanced photocatalytic activity (NO removal ratio of 64.9% and 60.7%) were fabricated via a facile sonochemical method. The visible light-harvesting ability of MCN-G and MCN-GO hybrids was enhanced and the conduction band was negatively shifted when 1.0 wt% graphene/graphene oxide was incorporated into the matrix of MCN. As electronic conductive channels, the G/GO sheets could efficiently facilitate the separation of chare carriers. MCN-G and MCN-GO exhibited drastically enhanced visible light photocatalytic activity toward NO removal. The NO removal ratio increased from 16.8% for CN to 64.9% for MCN-G and 60.7% for MCN-GO. This enhanced photocatalytic activity could be attributed to the increased surface area and pore volume, improved visible light utilization, enhanced reduction power of electrons, and promoted separation of charge carriers. This work demonstrates that a combined strategy is extremely effective for the development of active photocatalysts in environmental and energetic applications.

Keywords: Activity enhancement; Mesoporous g-C(3)N(4)/graphene; Mesoporous g-C(3)N(4)/graphene oxide; NO removal; Visible light photocatalytic.