A novel nitrogen-deficient g-C3N4 photocatalyst fabricated via liquid phase reduction route and its high photocatalytic performance for hydrogen production and Cr(VI) reduction

• Published in: Materials research bulletin Vol. 129; p. 110909
• Main Authors: Ma, Xiaoshuai, Zhang, Zhenmin, Yu, Changlin, Fan, Qizhe, Wei, Longfu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2020
• Subjects: Cr(VI) reduction; Formaldehyde; Hydrogen production; Liquid phase reduction; Nitrogen defects; Nitrogen defects; Liquid phase reduction; Cr(VI) reduction; Formaldehyde; Hydrogen production
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2020.110909

The hydrogen production rate of 30-CN with nitrogen defects is twice that of H-g-C3N4. [Display omitted] •Nitrogen-deficient g-C3N4 was fabricated by a liquid phase reduction method.•The extra electrons in nitrogen-deficient sites can capture photogenerated holes.•Nitrogen-deficient g-C3N4 has strong capacity for hydrogen production and Cr(VI) reduction.•Nitrogen-deficient brings about twice increase in hydrogen production. A facile liquid phase chemical reduction method was developed to synthesize nitrogen-deficient graphitic carbon nitride (FH-g-C3N4) by application of the weak reducibility of formaldehyde in weak acidic solution. The nitrogen defects in g-C3N4 were confirmed by EA, EPR, XPS and EDS. The extra electrons in nitrogen-deficient sites can easily capture photogenerated holes and reduce the recombination of photogenerated electrons and holes. With appropriate amount of nitrogen defects, FH-g-C3N4 possesses the best photocatalytic activity which is 58% higher than that of H-g-C3N4 (without nitrogen defects) and P25 (TiO2) for Cr(VI) reduction, and its hydrogen production rate is twice of the H-g-C3N4. Compared with H-g-C3N4, FH-g-C3N4 has a stronger light absorption capacity, a more negative potential of conduction band, and a stronger reduction capacity. This work could provide significant information for the simple synthesis of nitrogen-deficient g-C3N4 photocatalyst with distinct reduction performance.