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

Abstract

AbstractTiO2‐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 Ti3SiC2 (Al‐TSC or Sn‐TSC) is fabricated via a hot‐press 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−2 or 126.76 μA cm−2 which is 18 or 16 times higher than that of the anodized Ti3SiC2 (ATSC) (7.6 μA cm−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 TiO2 (Al‐TiO2) improve the visible light absorption capacity, for Sn‐ATSC is the suppressed recombination of hole‐electron pairs by the coupling effect of SnO2/TiO2.