Algarni, Zaina; Iqbal, Munawar; Younas, Umer; Mnif, Wissem; Din, Ghulam Mooin Ud; AKYÜREKLİ, Salih; Nazir, Arif; Ali, Faisal; Ali, Abid
Description:
The fabrication of effective electrocatalyst is critical for clean hydrogen generation via electrochemical water splitting. As potential candidates, carbon-based materials are likely to explore with in depth role as efficient, low cost and noncorrosive electrocatalysts. To this end, we used a facile hydrothermal technique to fabricate noble as well as transition metal catalysts on the surface of reduced graphene oxide (MO@rGO, MO = AgO and ZnO) for oxygen evolution reactions (OER). X-ray diffraction pattern and scanning electron microscopy (SEM) analysis revealed the nano sized range of synthesized AgO@rGO and ZnO@rGO electrocatalysts with high crystallinity and enhanced surface area to volume ratio by comprising the size of 37.17 nm and 27.89 nm, respectively. The OER performance of AgO and ZnO based rGO nanocomposites demonstrate a particularly high productivity, achieving current densities of 10 mA cm−2 at the overpotentials of 1.67 V and 1.70 V, respectively. The overpotential values and Tafel slopes were found to be 440 mV, 184 mV dec−1 and 470 mV, 212 mV dec−1 for AgO@rGO and ZnO@rGO respectively. Moreover, double layer capacitance of ZnO@rGO was recorded 38.02 μF cm−2 indicating higher electrochemical surface area as compared to AgO@rGO which was 15.2 μF cm−2. Chronoamperometric studies also provide supportive results elaborating effectiveness of the reported materials as efficient electrocatalysts towards OER.