Energy band modulation of N-doped rutile/anatase TiO_(2) photoanode promoting charge separation toward prominent photoelectrochemical performance

To solve the problem of high photogenerated carrier recombination rate and low photoelectric conversion efficiency of TiO_(2)-based materials,a simple N-doped anatase/rutile TiO_(2) heterophase nanorod film was designed by a low-temperature hydrothermal method in this work.The enhanced separation and transport of photogenerated charges were facilitated by the smaller contact barrier and appropriate band matching between anatase TiO_(2)nanoparticles and rutile TiO_(2) nanorods.The introduction of N doping in anatase TiO_(2) resulted in an upward shift of the valence band and a narrowing of the band gap,consequently enhancing the efficiency of visible light utilization.The combination of the heterophase junction and N-doping exhibited a synergistic effect,effectively suppressing the recombination of photogenerated charges and enhancing the photoelectric conversion efficiency of the photoanode.Under AM 1.5G irradiation,the photocurrent density(J)of the A-TO(N)@R-TONR photoanode reached2.19 mA·cm^(-2)(V_(RHE,1.23 eV)).Additionally,the incident photon-electron conversion efficiency(IPCE)and the charge injection efficiency(η)reached 81.4%and 51.6%at320 nm.Furthermore,the J,IPCE,andηvalues of the A-TO(N)@R-TONR photoanode were 2.96,2.1 and 3.2times those of pure R-TONR photoanode,respectively.This work presents a rational strategy for designing efficient TiO_(2)-based photoanodes.