Different Enhancement Mechanisms of the Anodizing Al‐Doped or Sn‐Coupled Ti₃SiC₂ for the Photoelectrochemical Performance

Abstract

TiO 2 -based photoanodes are very well known for their photoresponse performance, however, their inability to work in the visible range is still a challenge. To tackle this issue, Al-doped or Sn-coupled Ti 3 SiC 2 (Al-TSC or Sn-TSC) is fabricated via a hotpress sintering technique, and the anodized Al-TSC or Sn-TSC is abbreviated as Al-ATSC or Sn-ATSC. The Al-ATSC or Sn-ATSC with optimized doping content of Al or Sn corresponding to a superior photocurrent of 137.24 μA cm À 2 or 126.76 μA cm À 2 which is 18 or 16 times higher than that of the anodized Ti 3 SiC 2 (ATSC) (7.6 μA cm À 2 ) respectively. The capacitance for Al-ATSC or Sn-ATSC samples can be improved in the presence of visible light illumination. Enhanced photoelectrochemical (PEC) mechanism for Al-ATSC is that generated defects in Al doped TiO 2 (Al-TiO 2 ) improve the visible light absorption capacity, for Sn-ATSC is the suppressed recombination of hole-electron pairs by the coupling effect of SnO 2 /TiO 2 .[a] Prof.