Dual-functional silicon nanowire arrays-based photocatalytic fuel cell for solar-to-electricity conversion and self-powered glucose detection

Abstract

Developing a dual-functional photocatalytic fuel cell (PFC) with improved solar-to-electricity energy conversion efficiency and renewable biomass sensitivity performance is of great significance for clean energy conservation and utilization. Herein, a novel PFC device with stable signal output and glucose sensing performance is fabricated, of which polyaniline (PANI) functionalized p-type silicon nanowire arrays (SiNWs) and In2S3 modified n-type SiNWs are utilized as the photocathode and photoanode, respectively. The optimal PFC exhibits excellent cell performance under AM 1.5G illumination with an open circuit voltage of 0.83 V and a high-power density of 163.010 μW cm−2. The PFC also achieves effective glucose detection performance with a low detection limit of 0.998 μM and a broad linear range of 0∼50 mM, as well as excellent selectivity and stability. The enhanced performance is attributed to the efficient carrier separation and charge transfer rate at the interface of the heterojunctions, which is facilitated by the high conductivity of uniform PANI film on the p-SiNWs and S-scheme band alignment formed in the photoanodes. This work opens a new path for improving the energy conversion efficiency in traditional PFCs and offers guidance for sensing strategies toward renewable biomass using PFCs.