Carbon dots-Pt modified polyaniline nanosheet grown on carbon cloth as stable and high-efficient electrocatalyst for hydrogen evolution in pH-universal electrolyte

Abstract

Design and fabrication of hydrogen evolution reaction (HER) electrocatalysts with high activity, durability and moderate price are vital for realizing a viable water-splitting technology. Here, we demonstrate the carbon dots-Pt modified polyaniline nanosheets grown on carbon cloth (CDs/Pt-PANI) can serve as stable and high-efficient electrocatalyst in pH-universal electrolyte for HER. The overpotential for optimal CDs/Pt-PANI electrocatalyst can be lowered to 30 mV at 10 mA·cm−2 when Pt loading was only 8.1 μg·cm−2 (the Pt content in commercial 20 wt% Pt/C is 22.4 μg·cm−2), showing exceptional HER efficiency with a small Tafel slope 41.7 mV·dec−1 in acidic solution. Meanwhile, the optimal CDs/Pt-PANI electrocatalyst exhibits well stability with 17 mV potential shift after 20 h, which is 0.06 times than that of commercial 20 wt% Pt/C (286 mV). It is noticeable, the optimal CDs/Pt-PANI electrocatalyst is superior to 20 wt% Pt/C with HER performance in pH-universal electrolyte (acidic, neutral and basic). The efficient and stable HER performance of CDs/Pt-PANI should ascribe to the synergy in the CDs, Pt and PANI, in which the surface functional groups of CDs can connect tightly with PANI and improve the stability of Pt, simultaneously, the PANI and Pt provide the high-efficiency in HER.