Photoelectrocatalytic generation of H2 and S from toxic H2S by using a novel BiOI/WO3 nanoflake array photoanode

In this paper, a photoelectrocatalytic (PEC) recovery of toxic H2S into H2 and S system was proposed using a novel bismuth oxyiodide (BiOI)/ tungsten trioxide (WO3) nano-flake arrays (NFA) photoanode. The BiOI/WO3 NFA with a vertically aligned nanostructure were uniformly prepared on the conductive substrate via transformation of tungstate following an impregnating hydroxylation of BiI3. Compared to pure WO3 NFA, the BiOI/WO3 NFA promotes a significant increase of photocurrent by 200%. Owing to the excellent stability and photoactivity of the BiOI/WO3 NFA photoanode and $${{\rm{I}}^ - }{\rm{/I}}_3^ - $$ catalytic system, the PEC system toward splitting of H2S totally converted S2− into S without any polysulfide ( $${\rm{S}}_x^{n - }$$ ) under solar-light irradiation. Moreover, H2 was simultaneously generated at a rate of about 0.867 mL/(h ·cm). The proposed PEC H2S splitting system provides an efficient and sustainable route to recover H2 and S.