Non-noble Si NWs@ZnO core–shell heterojunction anode enables a photo-assisted mirco direct methanol fuel cell

Micro-direct methanol fuel cells (μ-DMFCs) show the promising feasibility in the various portable practical scenes, although the anode still remains the high cost and low anti-toxic ability of noble metal (viz. Pt). Using photo-responsive anodes to boost the performance of fuel cell activity and stability with the aid of light illumination has been as the new strategy and herein we construct core–shell structure of Si nanowires (NWs)@ZnO anode to investigate the performance of μ-DMFCs under light illumination. The short circuit current and open circuit voltage of Si NWs@ZnO heterojunction are 100.5 μA cm −2 and 0.7 V, respectively, which are 3.5 and 1.3 times higher than Si NWs under light illumination. The Si NWs@ZnO photoanode also kept 97.3 % of current density for the second reused. A record-high discharge voltage of 0.7 V and more than 12 h of discharge time were achieved in photo-assisted μ-DMFCs. Carefully designed core–shell structure and the matched energy levels between Si NWs and ZnO contribute to the significant improved performances, where they can attenuate the light reflexes of the polished silicon, strengthen photos absorption and boost the charge transfer kinetics. This study opens an appealing research direction based on photo-assisted non-noble semiconductor anode toward the high-performance μ-DMFCs.