Release time:2021-03-15  Hits:

• Key Words:BRIDGED COORDINATION POLYMER; THERMAL-DECOMPOSITION; HYDROGEN EVOLUTION; REDUCTION REACTION; ENERGY-STORAGE; ELECTROCATALYSTS
• Abstract:Intensive research is being conducted into highly efficient and cheap nanoscale materials for the electrocatalytic oxidation of water. In this context, we built heterostructures of multilayered CoNi-cyanide bridged coordination (CoNi-CP) nanosheets and graphene oxide (GO) sheets (CoNi-CP/GO) as a source for heterostructured functional electrodes. The layered CoNi-CP/GO hybrid components heated in nitrogen gas (N2) at 450 degrees C yield CoNi-based carbide (CoNi-C) through thermal decomposition of CoNi-CP, while GO is converted into reduced GO (rGO) to finally form a CoNi-C/rGO-450 composite. The CoNi-C/rGO-450 composite shows a reasonable efficiency for oxygen evolution reaction (OER) through water oxidations in alkaline solution. Meanwhile, regulated annealing of CoNi-CP/GO in N2 with thiourea at 450 and 550 degrees C produces CoNi-based sulfide (CoNi-S) rather than CoNi-C between rGO sheets co-doped by nitrogen (N) and sulfur (S) heteroatoms (NS-rGO) to form CoNi-S/NS-rGO-450 and CoNi-S/NS-rGO-550 composites, respectively. The CoNi-S/NS-rGO-550 shows the best efficiency for electrocatalytic OER among all electrodes with an overpotential of 290 mV at 10 mA cm(-2) and a Tafel slope of 79.5 mV dec(-1). By applying the iR compensation to remove resistance of the solution (2.1 O), the performance is further improved to achieve a current density of 10 mA cm(-2) at an overpotential of 274 mV with a Tafel slope of 70.5 mV dec(-1). This result is expected to be a promising electrocatalyst compared to the currently used electrocatalysts and a step for fuel cell applications in the future.
• Volume:12
• Issue:36
• Translation or Not:no