Combining iodic acid and nitric acid to fabricate carbon nitride tubes for enhanced hydrogen evolution under visible light

Abstract

This work presents a facile approach for preparing porous graphitic carbon nitride tubes with cyano groups and carbon vacancies (I/N-CN) through thermal polymerization of the pre-assembled melamine–cyanuric acid supramolecules from melamine by a mixed iodic acid/nitric acid assisted hydrothermal process. I/N-CN demonstrates 3.64-fold higher visible-light-driven hydrogen evolution rate (9.75 μmol h⁻¹) than the traditional tubular carbon nitride (HCN) prepared without iodic acid or nitric acid, originating from the promoted light absorption extending to the near-infrared region, accelerated electron transfer, inhibited recombination of charge carriers, higher reduction capability, more accessible active sites from the combination of porous tubular structure and enriched cyano groups and carbon vacancies.