La-Ni-MOF(BDC) composite with graphene oxide for enhanced bifunctional electrocatalysis in electrochemical water...

Highly efficient electrocatalysts use graphene sheets that are abundant in nature create considerable importance during the complete process of water splitting because they enable sustainable energy conversion and storage. Study presents metal-organic frameworks (MOFs) which researchers synthesize through hydrothermal methods together with graphene oxide (GO) to use in electrochemical water splitting as an electrocatalytic material. The research aims to create non-precious metal bifunctional catalysts which will operate successfully through both anodic oxygen evolution reaction (OER) and cathodic hydrogen evolution reaction (HER) processes. The researchers produced La-Ni based MOFs through synthesis which they combined with GO to enhance their electrocatalytic performance. The La-Ni-MOF/GO material achieved dual performance through its superior output to produce hydrogen at 0.39 V and 93 mV at 10 mA cm^- 2 and its superior output to produce oxygen at 2.31 V and 184 mV at 10 mA cm^- 2. The electrochemical analysis revealed faster reaction kinetics because the Tafel slope measured 51 mV dec^- 1 during HER and 47 mV dec^- 1 during OER. The composite material reached its minimum charge transfer resistance at Rct = 4.3 Ω for OER and 556 Ω for HER while showing its highest turnover frequency at TOF = 1.34 s^- 1 and maintaining excellent long-term stability throughout 50 h. The excellent properties in La-Ni-MOF/GO occur because the combination of Ni, La and GO promotes the optimal charge transfer, increased active site exposure and enhanced electrical conductivity through multiple mechanisms. The presence of the organic linker, terephthalic acid incorporation, adds also increased separation between the metal ions as well as increased active site availability whilst maintaining the structural integrity of the composite compound. In this work, we present the potential for using La-Ni MOFs combined with Graphene Oxide to create an innovative bifunctional electrocatalytic material with enhanced charge transfer, increased number of available active sites and increased stability over time. This new low-cost scalable strategy will provide an exceptionally high-performance long-term catalyst for producing hydrogen from water using electrocatalytic water-splitting processes to support future developments in renewable energy conversion technologies.