Self-Healing Graphene-Templated Platinum–Nickel Oxide Heterostructures for Overall Water Splitting

Abstract

Electrocatalysts with dramatically enhanced water splitting efficiency, derived from controlled structures, phase transitions, functional activation, etc., have been developed recently. Herein, we report an in situ observation of graphene-based self-healing, in which this functional activation is induced by a redox reaction. Specifically, graphene on stainless steel (SUS) switches between graphene (C–C) and graphene oxide (C–O) coordination via an electrical redox reaction to activate water splitting. A heterostructure comprising Pt-NiO thin films on single-layer graphene directly grown on a SUS substrate (Pt-NiO/Gr-SUS) was also synthesized by electrodeposition. Pt-NiO/Gr-SUS exhibited water splitting activity with low Pt loading (<1 wt %). The findings provide valuable insight for designing robust electrodes based on reversible redox-induced self-healable graphene to develop more efficient catalysts.

Construction of MnxCoyO4/Ti electrocatalysts for efficient bifunctional water splitting

“…S4, † the electric double layer capacitance C dl values of different samples can be calculated from the scanning rate and cyclic voltammograms (CV), and the Mn x Co y O 4 /Ti (Mn : Co = 1 : 2) catalyst has a higher C dl value than the other catalysts, and it has the highest electrochemical active surface area, which will be conducive to the exposure of the catalyst active sites. 59,60 Mn x Co y O 4 /Ti (Mn : Co = 1 : 2) has a C dl of 23.53 mF cm −2 , Mn x Co y O 4 /Ti (Mn : Co = 1 : 1) has a C dl of 7.14 mF cm −2 and Mn x Co y O 4 /Ti (Mn : Co = 2 : 1) has a C dl of 16.5 mF cm −2 (Fig. S9 †), indicating that Mn x Co y O 4 /Ti (Mn : Co = 1 : 2) has a high electrochemical active area and abundant catalytic active sites on the surface (Fig.…”

Surface-Regulated Platinum–Copper Nanoframes in Electrochemical Reforming of Ethanol for Efficient Hydrogen Production

“…To accelerate the development of this emerging field, more attention should be paid to designing efficient bifunctional electrocatalysts for HER and EOR. Some platinum (Pt)-based materials have showed excellent performance in HER and small molecule oxidation reactions, demonstrating their amazing properties in this realm. − However, the performance and practical application of Pt are subjected to its high cost, weak adsorption capacity for ethanol and H 2 O molecules, as well as the weak dissociation capacity for C–H bonds in ethanol, resulting in poor selectivity to ethanol-selective oxidation products, and so forth . Introducing foreign elements to form Pt-based alloy materials could enhance electron conductivity, optimize the electron structure, and provide sufficient synergistic function of the material.…”

Optimal rule-of-thumb design of NiFeMo layered double hydroxide nanoflakes for highly efficient and durable overall water-splitting at large currents

“…Transition metal oxides have also been extensively investigated as a promising alternative for the OER in alkaline media due to the multiple valence states of transition metals. [3][4][5][6][7][8] Although the lattice-oxygen oxidation mechanism (LOM) has been proposed, Pourbaix diagrams of the elements involved in the OER indicate that the process oen requires a higher potential for the oxidation of metal species. [9][10][11][12] Therefore, it is difficult to develop highly oxidized species while minimizing their formation energy.…”