Cobalt Based Nanoparticles Embedded Reduced Graphene Oxide Aerogel for Hydrogen Evolution Electrocatalyst

Abstract

Efficient water electrolysis catalyst is highly demanded for the production of hydrogen as a sustainable energy fuel. It is reported that cobalt derived nanoparticle (CoS2, CoP, CoS|P) decorated reduced graphene oxide (rGO) composite aerogel catalysts for highly active and reliable hydrogen evolution reaction electrocatalysts. 7 nm level cobalt derived nanoparticles are synthesized over graphene aerogel surfaces with excellent surface coverage and maximal expose of active sites. CoS|P/rGO hybrid aerogel composites show an excellent catalytic activity with overpotential of ≈169 mV at a current density of ≈10 mA cm−2. Accordingly, efficient charge transfer is attained with Tafel slope of ≈52 mV dec−1 and a charge transfer resistance (Rct) of ≈12 Ω. This work suggests a viable route toward ultrasmall, uniform nanoparticles decorated graphene surfaces with well‐controlled chemical compositions, which can be generally useful for various applications commonly requiring large exposure of active surface area as well as robust interparticle charger transfer.

Uncovering Key Factors in Graphene Aerogel-Based Electrocatalysts for Sustainable Hydrogen Production: An Unsupervised Machine Learning Approach

“…Electrocatalysts based on the use of three-dimensional (3D) porous nanostructured materials have a lot of potential in this field. Their improved electrocatalytic efficiency is due to subtleties embedded within the catalyst's design, stressing that the efficacy of these materials is dependent on the overall configuration and structural properties of the catalyst [17][18][19]. According to research findings, three-dimensional (3D) porous architecture, which is created through the assembly of molecular precursors or low-dimensional nanostructures, not only includes intrinsic properties derived from its confined dimensions but also demonstrates emergent properties.…”

Sulfur-Rich N-Doped Co9S8 Catalyst for Highly Efficient and Durable Overall Water Electrolysis Application

“…However, their bifunctionality lags behind than that of the precious-metal-based catalysts due to inefficient kinetics in a single electrolyte medium [3]. For example, due to its high conductivity, intrinsic kinematics, robustness, mixed valence state, and efficient and durable electrochemical activity, Co 9 S 8 is considered a promising electrocatalyst material [13][14][15], but it suffers from poor electrochemical activity arising from its sluggish kinetics during catalytic OER and HER processes [18][19][20]. The catalytic activity of an electrocatalyst is mainly determined by its electronic structure, which can be altered intrinsically via the addition of heteroatoms (e.g., N and S) to the host structure [21,22].…”