Facile synthesis of macroporous silicon photocathodes with enhanced photoelectrochemical performance

Macroporous n-type silicon photocathodes were successfully prepared using an electrochemical etching method under constant current electrolysis at 40 mA cm−2. We found that comparing with planar n-type and etching p-type silicon photocathodes, the macroporous n-type silicon photocathodes exhibited considerably higher photocurrent response and photoelectrochemical(PEC) performance in terms of H2 generation under visible light irradiation without requiring a catalyst or a sacrificial agent. This study provides an alternative method of preparing porous silicon and introduces a new photocatalyst or support for noble-metal nanophotocatalysts for PEC water splitting.