Template-Free Synthesis of Boron-Doped Graphitic Carbon Nitride Porous Nanotubes for Enhanced Photocatalytic Hydrogen Evolution
S.F. Zhang, S.F. Zhang, Changsheng An, Rongchao Zhang, Dezhi Kong, Difa Xu, Shiying Zhang, Shiying Zhang
Abstract
The photocatalytic activity of g-C 3 N 4 can be enhanced by improving photoinduced carrier separation and exposing sufficient reactive sites. In this study, we synthesized B-doped porous tubular g-C 3 N 4 (BCNT) using a H 3 BO 3 -assisted supramolecular self-template method, wherein H 3 BO 3 helped in B-doping, building a porous structure, and maintaining one-dimensional nanotubes. The tubular structure had an ultrathin tube wall and large aspect ratio, which are conducive to the directional transmission and separation of photogenerated carriers; moreover, the abundant pore structure of the tube wall could fully expose the reactive sites. The introduction of B and the cyano group modulated the bandgap of g-C 3 N 4 and elevated the position of the conduction band, thus enhancing the photoreduction ability and effectively improving the hydrogen evolution performance. Consequently, the hydrogen evolution of BCNT-2 (220.8, 53.2 μmol·h –1 ) was 1.82 and 1.54 times that of ultrathin g-C 3 N 4 nanosheets (CNN, 121.3, 34.6 μmol·h –1 ) under simulated sunlight and LED lamp irradiation, respectively. Thus, this work provides in-depth insights into the rational design of one-dimensional g-C 3 N 4 nanotubes with high hydrogen evolution activity under visible irradiation.