Platinum nanoparticles deposited nitrogen-doped carbon nanofiber derived from bacterial cellulose for hydrogen evolution reaction

摘要

The nitrogen-doped carbon nanofiber derived from low and high proportion polyaniline doped bacterial cellulose (BC) was obtained via polymerization followed by pyrolysis. The resulting products were named LN-BC and HN-BC accordingly. Platinum nanoparticles modified LN-BC and HN-BC was then prepared (PORN-BC and Pt@HN-BC) via electrochemical deposition. The morphologies of LN-BC and HN-BC indicated that the BC lost its nanowire structure after polyaniline modification and pyrolysis under nitrogen atmosphere. Platinum nanoparticles with diameters ranging from 3 to 5 nm can be well dispersed in the HN-BC support. The HER performance of Pt@LN-BC and Pt@HN-BC was fully investigated. Electrochemical results showed that the Pt-based catalysts had better HER activity than the Pt free catalysts in acid, indicating the HER activity was mainly from Pt. Besides, Pt@HN-BC had better HER activity than Pt@LN-BC in acid, suggesting N-doping rate was an important factor in enhancing HER activity. And the 10Pt@HN-BC (deposition for 10 s) with 4.38 wt% Pt loading was the best HER catalyst among the Pt@HN-BC. The onset potential (@ -1 mA cm(-2)) and overpotential (@ -10 mA cm(-2)) of the 10Pt@HN-BC in 0.5 M H2SO4 is -18 and -47 mV, respectively. The corresponding Tafel slope was -35 mV dec(-1), which is quite comparable to that of Pt/C (10 wt%). The electrochemical double layer capacitance (C-dl) and turnover frequency (TOF) were estimated and presented in the work. Long-term stability test confirmed that the 10PtCHN-BC had excellent stability, which was important for practical application. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.