Boosting of water splitting using the chemical energy simultaneously harvested from light, kinetic energy and electrical energy using N doped 4H-SiC nanohole arrays

Piezoelectric polarization promoted photoelectrochemical (PE-PEC) water splitting is a promising strategy to obtain hydrogen energy by converting light, kinetic, and electrical energy into chemical energy . However, novel piezoelectric semiconductors are urgently needed owing to the improper band positions and poor stability of most current piezoelectric materials . In this work, a method of inducing piezopotential in N doped 4H-SiC nanohole arrays (NHAs) for water splitting is proposed. The modulation effects of N doping with various contents on the electronic structure and piezoelectricity of 4H-SiC are comprehensively analyzed. By introducing piezoelectric field to regulate transport behavior of charges, the current density of NHAs reaches 6.50 mA cm −2 at 1.4 V Ag/AgCl , indicating a 50.1% enhancement compared with that without polarization (4.33 mA cm −2 at 1.4 V Ag/AgCl ). The conjunction mechanism of photoelectric catalytic capacity and piezoelectricity of N doped 4H-SiC NHAs is elaborated, providing powerful guidance for manufacturing piezoelectric semiconductor photoanodes in PE-PEC water splitting.