TiO2/Ti3C2 intercalated with g-C3N4 nanosheets as 3D/2D ternary heterojunctions photocatalyst for the enhanced photocatalytic reduction of nitrate with high N2 selectivity in aqueous solution. Issue 10 (7th April 2021)

• Record Type: Journal Article
• Authors: Zheng, Rui; Li, Chunhu; Huang, Kelei; Guan, Ying; Sun, Bo; Wang, Wentai; Wang, Liang; Bian, Junjie
• Is Part Of: Inorganic chemistry frontiers. Volume 8:Issue 10(2021)
• Page Start: 2518
• Page End: 2531
• Publication Date: 2021-04-07
• Subjects: Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d1qi00001b
• Languages: English
• ISSNs: 2052-1553

Abstract

Abstract : TiO2 /Ti3 C2 intercalated with g-C3 N4 nanosheets as 3D/2D ternary heterojunctions photocatalyst was fabricated. Its performance of photocatalytic nitrate reduction was enhanced with Z-scheme heterojunction under irradiation. Abstract : Recently, nitrate as one of the water pollutants has caused widespread concerns. The nitrite and ammonium of nitrate reduction products have also been regarded as contaminants. Thus, increasing the nitrate removal rate and improving the nitrogen selectivity simultaneously have attracted the attention of researchers. To remove the nitrate with high nitrogen selectivity from an aqueous solution, 2D g-C3 N4 was intercalated into 3D TiO2 /Ti3 C2 to fabricate the TiO2 /Ti3 C2 /g-C3 N4 photocatalyst with 3D/2D ternary heterojunctions. 0.5 TiO2 /Ti3 C2 /g-C3 N4 photocatalyst exhibited the highest nitrate conversion and nitrogen selectivity, which reached 93.03% nitrate conversion and 96.62% nitrogen selectivity after 40 min of irradiation. Moreover, its photocatalytic performance remained stable after 5 cycles. It was observed that the high concentration of nitrite was advantageous for improving the nitrogen selectivity. In TiO2 /Ti3 C2 /g-C3 N4 composites, 3D Ti3 C2 served not only as a template for preparing 2D g-C3 N4, but also as a channel for the electron transfer between TiO2 and g-C3 N4 . Photogenerated electrons in the conduction band of TiO2 migrated to the valence band of g-C3 N4 through Ti3 C2 . The corresponding holes remained on the valence band of TiO2 and were captured by formic acid in an aqueous solution to generate reducing COO˙ − . Then, COO˙ − in the solution and photoinduced electrons in the conduction band of g-C3 N4 reduced nitrate to nontoxic and harmless nitrogen with high selectivity. Finally, the Z-scheme heterojunction was proposed over 0.5 TiO2 /Ti3 C2 /g-C3 N4 photocatalyst on working for the photocatalytic nitrate reduction in water.