Unique construction of hierarchical PANI–based nanofibrous network for boosting water electrolysis through highly efficient utilization of Pt nanocatalyst

Enhancing catalytic activity of Pt and designing rational structure of catalytic layer (CL) are effective strategies for improving the performance of proton exchange membrane water electrolysis (PEMWE) with lower Pt loading. Herein, a hierarchical nanostructured CL based on co–doped carbon, sulfonated polyaniline (PANI) nanofibrous network and Pt nanoparticles is constructed on carbon cloth by layer–by–layer in–situ growth method. The N/P/S co–doped carbon interlayer derived from PANI can promote the growth of sulfonated PANI nanofibers. The in–situ grown Pt nanoparticles is anchored by sulfonated PANI, achieving uniform and stable distribution as well as altered electronic structure for improved catalytic activity. The unique CL greatly improves the electrochemical surface area and provides interconnected pathways. The as–prepared cathode exhibits an overpotential of 23 mV at 10 mA cm−2, indicating excellent hydrogen evolution performance. Furthermore, the PEMWE device with above–mentioned cathode achieves an excellent performance of 1.771 V @ 2 A cm−2 with low Pt loading of 0.07 mg cm−2, which is comparable to that of the conventional cathode with 14 times higher Pt loading of 1 mg cm−2. Our strategy of designing hierarchical nanostructured CL provides a feasible approach to lower the consumption of Pt without performance loss for further industrialization of PEMWE.