Bifunctional colloid based on anchoring reactions in-situ modified electrodes: For electrochemical sensing and HER

Abstract

In this study, a bifunctional [PtCl6]2−-GO colloidal material was prepared by anchoring [PtCl6]2− by abundant oxygen-containing functional groups in protonated graphene oxide. Two modification strategies, surface overcoating and electrochemical in situ deposition, were adopted to modify the screen-printed carbon electrode (SPCE), foam electrodes (CuF, NiF), respectively, and Pt-rGO, which uniformly covered the electrode surface, was obtained by a simple onestep of reducing [PtCl6]2−-GO. The effectiveness of the modified materials and electrode modification strategies prepared was validated by tinidazole electrochemical detection and hydrogen evolution reaction (HER). The results indicated that the Pt-rGO modified SPCE possessed lower LOD and higher sensitivity for the detection. Furthermore, as for HER, optimized Pt-rGO-modified NiF and CuF required only 26 mV and 76 mV overpotentials in alkaline and acidic solutions, respectively, to obtain current densities of 10 mA cm−2. This was largely ascribed to the synergistic interaction between platinum and rGO, with the synthesized platinum-rGO displaying stronger active sites and higher intrinsic activity. In particular, Pt, which acts as an active center, could offer part of its electron to H2O and adjacent reduced graphene oxide sites, thus promoting strong electrical connections and efficient HER kinetics.