Efficient Visible-Light-Responsive Photocatalytic Fuel Cell with a ZnIn2S4/UiO-66/TiO2/Ti Photoanode for Simultaneous RhB Degradation and Electricity Generation

Abstract

In order to enhance the photoelectric conversion efficiency of a photoanode and broaden its light absorption range, a ZnIn2S4/UiO-66/TiO2/Ti composite photoanode was developed. The maximum photocurrent density of the prepared photoanode is 2.56 mA cm−2 at 1.2 V (versus SCE), which is 1.79 times higher than that of ZnIn2S4/TiO2/Ti. The rhodamine B (RhB) removal rate, short-circuit current density and maximum power density of a photocatalytic fuel cell (PFC) constructed with the ZnIn2S4/UiO-66/TiO2/Ti photoanode and a Cu cathode are 98.01%, 0.22 mA cm−2 and 16.97 μW cm−2 respectively. The enhancement of the PFC performance is mainly attributed to the extremely good energy band matching and nano-size interface contact between ZnIn2S4 and UiO-66. The existence of UiO-66 can be as an electronic transmission bridge, which not only facilitates the rapid transfer and utilization of photogenerated electrons, but also improves the adsorption ability of the photoanode for RhB molecules. Graphical Abstract: [Figure not available: see fulltext.]