Tubular Carbon Nitride with Hierarchical Network: Localized Charge Carrier Generation and Reduced Charge Recombination for High-Performance Photocatalysis of H_2 and H_2O_2 Production

摘要

Polymeric carbon nitride (PCN), as an appealing metal-free and low-cost photocatalystfor solar-to-fuel conversion, is still suffering from insufficient lightharvestingefficiency and short excited state lifetime of electron–hole pairs.Herein, a 3D hierarchical network of carbon nitride tubes (NCNT) with intercrossingfew-layer tubes of uniform diameter, synthesized by a synergisticstrategy of tailoring the chemical and hydrogen bond, is reported. This hollownetwork structure facilitates the internal light reflection, thus promoting the lightinducedelectron–hole pair generation. Moreover, the few-layer NCNT withnitrogen defects effectively decreases the undesired electron–hole recombination.These advantages are disclosed by experimental spectra and finite differencetime domain (FDTD) simulations and density functional theory (DFT) calculations.Impressively, the optimized NCNT exhibits almost 32 times the photocatalytichydrogen evolution ability (8.6mmol h~(-1) g~(-1)) and 4 times (485.7 μmol h~(-1) g~(-1))the hydrogen peroxide production of those of bulk PCN, respectively. This workprovides a new strategy to construct a hierarchical nanostructure of a highperformancecarbon nitride photocatalyst through enhancing the solar-lightcapture and conversion.