Hollow Carbon Cages Derived from Polyoxometalate‐Encapsuled Metal‐Organic Frameworks for Energy‐Saving Hydrogen Production

Abstract

The electrocatalytic conversion of water‐to‐hydrogen powered by renewable energy is one of the promising strategies to unravel the energy and environment crises. However, a such process usually costs large energy consumption owing to the low efficiency of anodic oxygen evolution reaction (OER), which is another vital half reaction of the overall water splitting (OWS) system. Herein, we designed and fabricated hollow nitrogen‐doped carbon nanocages loaded with Ni3N and Co nanoparticles derived from polyoxometalate‐encapsuled metal‐organic frameworks. The catalyst exhibited appealing dual functions for both OER and hydrogen evolution reaction (HER), outperforming the Ni‐free and solid samples. Notably, the designed catalyst also showed much enhanced electrochemical performance for glycerol/glucose oxidation reaction when compared with OER. The home‐made two‐electrode electrolyzer, coupled HER with polyalcohol or glucose oxidation reaction, only needs cell voltages of 1.125 and 1.557 V to reach 10 mA cm−2, respectively, which are much smaller than that in 1 M KOH (2.087 V), demonstrating a large amount of energy saving for hydrogen production.

Cathode materials for halide-based aqueous redox flow batteries: recent progress and future perspectives

“…81 The uneven charge distribution of semiconductor junctions via enhanced charge transfer activities improves the activity of cobalt sulfide-based electrocatalysts. 82 Positive and negative electrodes can significantly boost the electrochemically catalyze activities of I − /I 3− and S 2− /S x 2− redox reactions, meanwhile, improving the absorptivity of the charged ions and promoting charge transfer. Copper-based chalcogenides have been widely investigated as electrodes to efficiently catalyze the redox reactions of the polysulfide couple to improve the conversion efficiency.…”

Structural Design Induced Electronic Optimization in Single‐Phase MoCoP Nanocrystal for Boosting Oxygen Reduction, Oxygen Evolution, and Hydrogen Evolution

“…[22] Most of the preparations of porous carbon materials are based on hardtemplate methods and metal-organic frameworks, but the complicated preparation process limits their large-scale commercial application. [23][24][25] Polytetrafluoroethylene (PTFE) microsphere as a soft template is promptly developed and applied to prepare porous carbon substrates. After heating treatment, a porous structure was gradually formed on the carbon skeleton as PTFE evaporation, which simplifies the preparation process.…”

A macroporous carbon nanoframe for hosting Mott–Schottky Fe–Co/Mo2C sites as an outstanding bi-functional oxygen electrocatalyst

“…22 Although the design of Mott–Schottky-type catalysts can provide a feasible strategy for charge transport, the issue of poor mass transport presents a challenge to achieving enhanced catalytic activity, mainly due to the low accessibility of active centers inside the catalyst. 23 Previous studies have indicated that efficient electrocatalysts with high conductivity and a desirable macroporous nanoframe structure can promote rapid mass/charge transport and robust triple-phase interfacial catalysis. 24 Therefore, there is a growing demand for developing efficient ORR-OER catalysts that exhibit both the Mott–Schottky effect for rapid charge transport and macroporous structures for smooth mass transfer.…”