Template-free preparation of non-metal (B, P, S) doped g-C3N4 tubes with enhanced photocatalytic H2O2 generation

Abstract

• The g-C 3 N 4 tube (CNT) with a porous surface was prepared by a template by a template-free and environmental-friendly process. • The doped non-metals (B/P/S) in CNT can significantly enhance the photocatalytic H 2 O 2 production. • The excellent photocatalytic activity of doped CNT is attributed to the synergistic effects of morphology and doping. • The ·O 2 − is the dominant active specie in photocatalysis and the H 2 O 2 is generated from two-step single-electron O 2 reduction. Developing environmentally friendly methods to produce hydrogen peroxide (H 2 O 2 ) has received increasing attention. Photocatalysis has been proved to be a sustainable technology for H 2 O 2 production. Herein, the novel non-metal elements (B, P, and S) doped g-C 3 N 4 tubes (B-CNT, P-CNT, and S-CNT) photocatalysts were obtained via a hydrothermal synthesis followed by thermal polymerization. By adjusting the precursor, the yield of g-C 3 N 4 tubes (CNT) materials has been greatly improved. The as-prepared B-CNT, P-CNT, and S-CNT photocatalysts show an enhanced photocatalytic H 2 O 2 production with the formation rate constants values of 42.31 μM min −1 , 24.95 μM min −1 , and 24.22 μM min −1 , respectively, which is higher than that of bulk CN (16.40 μM min −1 ). The doped B, P, S elements significantly enhanced the photocatalytic activity by adjusting their electronic structures and promoting the separation of electron-hole carriers. The results have shown great potential for the practical application of CNT photocatalysts.