Zeolitic imidazolate framework derived cobalt oxide anchored bacterial cellulose: a good template with improved H2O adsorption ability and its enhanced hydrogen evolution performance

Abstract Electrochemical water splitting has been confirmed as one of the effective methods to produce hydrogen. Effective electrocatalyst with low dynamic overpotential and long durability is an important factor in hydrogen evolution reaction (HER). In present work, a cobalt oxide derived from zeolitic imidazolate framework (ZIF-67) was anchored on bacterial cellulose (BC) to construct a ZIF-67/BC nanostructure firstly. Then, trace amount of palladium and platinum bimetal were deposited on the surface of ZIF-67/BC for various times via electrodeposition to form xPtPd@ZIF-67/BC (x was the electrodeposition time). The optimized electrocatalyst, 10PtPd@ZIF-67/BC with 0.07 wt% Pt and 0.23 wt% Pd loading showed superior electrochemical activity and HER performance in both acidic and alkaline media. The overpotential (@ 10 mA cm-2) was 59 and 33 mV in 0.5 M H2SO4 and 1.0 M KOH, respectively. The corresponding Tafel slope was 17 and 87 mV dec-1, respectively. The 10PtPd@ZIF-67/BC also displayed a good durability after 5000 cycles and 24 h of continuous electrolysis in 0.5 M H2SO4 and 1.0 M KOH. The ZIF-67/BC template could effectively enhance the H2O adsorption and improve dispersion of noble metalic nanoparticles. The presence of Pd enhanced hydrogen adsorption and further increased the electrocatalytic performance of 10PtPd@ZIF-67/BC.