One-pot synthesis of sodium-doped willow-shaped graphitic carbon nitride for improved photocatalytic activity under visible-light irradiation

Qian Dou; Jianhua Hou; Asif Hussain; Geshan Zhang; Yongcai Zhang; Min Luo; Xiaozhi Wang; Chuanbao Cao

doi:10.1016/j.jcis.2022.05.085

One-pot synthesis of sodium-doped willow-shaped graphitic carbon nitride for improved photocatalytic activity under visible-light irradiation

J Colloid Interface Sci. 2022 Oct 15:624:79-87. doi: 10.1016/j.jcis.2022.05.085. Epub 2022 May 17.

Authors

Qian Dou¹, Jianhua Hou², Asif Hussain¹, Geshan Zhang³, Yongcai Zhang⁴, Min Luo⁵, Xiaozhi Wang⁶, Chuanbao Cao⁷

Affiliations

¹ College of Environmental Science and Engineering, Yangzhou University, Yangzhou 225000, PR China.
² College of Environmental Science and Engineering, Yangzhou University, Yangzhou 225000, PR China; Guangling College, Yangzhou University, Yangzhou 225009, PR China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210095, PR China. Electronic address: jhhou@yzu.edu.cn.
³ College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, PR China.
⁴ College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225000, PR China.
⁵ College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan, Ningxia 750021, PR China.
⁶ College of Environmental Science and Engineering, Yangzhou University, Yangzhou 225000, PR China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210095, PR China.
⁷ Research Center of Materials Science, Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, Beijing Institute of Technology, Beijing 100081, PR China.

PMID: 35660913
DOI: 10.1016/j.jcis.2022.05.085

Abstract

Graphitic carbon nitride (g-C₃N₄) is considered as a promising low-cost polymeric semiconductor as conjugated photocatalyst for energy and environmental application. This study exhibits a Na-doped g-C₃N₄ with willow-leaf-shaped structure and high degree of crystallinity, which was synthesized with a convenient thermal polymerization using sodium carbonate (Na₂CO₃) as the sodium source. The π-conjugated systems of g-C₃N₄ were improved by doping sodium, which could accelerate the electron transport efficiency resulting in outstanding photocatalytic properties. Furthermore, optimum Na-doped g-C₃N₄ (CN-0.05) attributed its enhanced irradiation efficiency of light energy to its narrower band gap and significant improvement in charge separation. Consequently, the H₂ evolution rate catalyzed with CN-0.05 can achieve 3559.8 μmol g^-1 h^-1, which is about 1.9 times higher than that with pristine g-C₃N₄. The rate of CN-0.05 for reduction of CO₂ to CO (3.66 μmol g^-1 h^-1) is 6.6 times higher than that of pristine g-C₃N₄. In experiments of pollutants degradation, the reaction constants of degradation of rhodamine B (RhB) and methyl orange (MO) with CN-0.05 were 0.0271 and 0.0101 min^-1, respectively, which are 4.7 and 7.2 times more efficient than pristine g-C₃N₄, respectively. This work provides a simple preparation method for tailoring effective photocatalyst for the sustainable solution of environmental issues.

Keywords: CO(2) reduction; G-C(3)N(4); Na-doped; Photocatalytic H(2) evolution; Pollutant degradation.