Atomically confined calcium in nitrogen-doped graphene as an efficient heterogeneous catalyst for hydrogen evolution

Abstract

Summary Calcium is one of the most abundant and cheapest elements on earth. However, due to the lack of d-orbitals for chemical adsorption, it is generally considered as a stoichiometric reagent with no catalytic activities in heterogeneous catalysis. In this research, we have revealed that atomically confined Ca in nitrogen-doped graphene (Ca 1 -NG) can be an effective heterogeneous catalyst to boost both electrocatalytic and photocatalytic hydrogen evolution reactions (HER). Ca single atoms anchored in NG can efficiently enhance the HER performance due to the improvement of the interfacial charge transfer rate and suppression of the photo-generated charge recombination. Density functional theory calculations show that the high catalytic activity of Ca 1 -NG results from the Ca single atoms in NG, which leads to multiple H adsorption configurations with favorable ΔG H∗ values for HER. This research can be valuable for the designing of environmentally friendly, economical and efficient catalysts for renewable hydrogen production.

Diatomic Pd−Cu Metal‐Phosphorus Sites for Complete N≡N Bond Formation in Photoelectrochemical Nitrate Reduction

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Multi-functional O2–H2 electrochemistry by an abundant mineral: a novel and sustainable alternative for noble metals in electrolyzers and metal–air batteries

“…57,58 Meanwhile, we assume that calcium in HAG plays a bifunctional role in water splitting based on its well-known participation in natural water splitting in green leaves. 59,60 Though scarce, calcium has also been reported to promote ORR. 61 Nevertheless, a dedicated theoretical study can only reveal the true role of the active sites in the HAG toward its remarkable multifunctionality.…”

Recent Progress in Graphene-Based Electrocatalysts for Hydrogen Evolution Reaction

“…Sun et al [ 71 ] prepared Ca1-NG non-homogeneous catalysts using graphene oxide (GO) and CaCl 2 in NH 3 atmosphere, in which N, Ca, and C elements were homogeneously doped in the graphene lattice, with a minor Tafel slope and an overpotential of 151 mV at a current density of 10 mA/cm 2 .…”