화학공학소재연구정보센터
International Journal of Hydrogen Energy, Vol.44, No.8, 4208-4217, 2019
New method for improving the bulk charge separation of hematite with enhanced water splitting
Due to its poor bulk charge separation efficiency, the photoelectrochemical (PEC) performance of pristine hematite prepared directly from an electrodeposited Fe film is limited. Au-modification of hematite via a simple immersion method improves the PEC performance two-fold to 0.31 mA cm(-2). The Au nanoparticles deposited from HAuCl4 act as plasmonic photosensitizers and electron collectors to improve the light absorption and bulk charge separation efficiency of the photoanode. In addition, the increase in the (110) plane and specific surface area induced by HAuCl4 enhances the bulk charge separation efficiency. After further modification with Ti, the photocurrent response of the resulting Ti/Au/alpha-Fe2O3 photoanode improves to 0.51 mA cm(-2); this increase is attributed to its increased light absorption, bulk charge separation efficiency (eta(bulk)), and surface charge injection efficiency (eta(surface)). In this work, the effect of Au and Ti on the crystalline structure, morphology and PEC performance of the novel electrodeposited hematite photoanode are investigated by systematical characterization.