V₄P_6.98/VO(PO₃)₂ as an Efficient Non‐Noble Metal Catalyst for Electrochemical Hydrogen Evolution in Alkaline Electrolyte

Abstract

Electrocatalytic water splitting for hydrogen production shows great potential for developing hydrogen as an energy source, owing to its low energy consumption and high-purity products. Developing non-noble metal hydrogen evolution reaction (HER) catalysts with a high activity for water splitting in alkaline media is urgent and challenging. Herein, we synthesized a flower-like V 4 P 6.98 /VO(PO 3 ) 2 catalyst on a nickel foam substrate as an efficient non-noble metal catalyst for electrochemical hydrogen evolution in alkaline electrolyte. The catalyst showed high catalytic performance for HER, requiring an overpotential of 159 mV to achieve 10 mA/cm 2 , and displayed long-term stability in alkaline medium. We report a low-cost and high-efficiency non-noble metal HER catalyst beyond the commonly used transition metals (Ni, Co, Mo, Cu, and Fe), which expands the scope of non-noble-metal phosphide catalysts for water splitting.Rising energy demand and environmental concerns have raised public awareness of the need to replace fossil fuels with renewable and carbon-neutral energy sources. Hydrogen is recognized as an ideal choice for a sustainable energy economy and is also widely used in industrial production and daily life. [1] Electrocatalytic water splitting for hydrogen production shows great potential for developing hydrogen as a new energy source owning to its low-energy consumption and high-purity products. [2] To date, noble metals catalysts based on Pt, Ru, and Ir have exhibited high activities for water splitting; however, the high cost and scarcity of noble metals become two biggest obstacles for practical applications on a large scale. The oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) were two essential part of overall water-splitting process. And OER is the rate-determining reaction in this process, requiring the transfer of four electrons. [3] Generally, HER catalysts operate under acidic conditions, whereas OER is conducted in alkaline media. This pH mismatch makes it difficult to assemble cells with both HER and OER catalysts for water splitting, and often leads to poor overall performance. Thus, it remains challenging to develop non-noble metal HER catalysts with a high activity for water splitting in alkaline media.Non-noble metal catalysts based on Co, [4][5][6][7][8] Ni, [9][10][11][12][13][14] Fe, [15][16][17] and Mo [5,[18][19][20] have been intensively used as HER catalysts owing to the high abundance of these elements and the their low cost, and high catalytic activities. In the past few years, V-based oxides, sulfides, and nitrides show promise for applications in the field of energy conversion and storage, such as supercapacitors and rechargeable batteries for their high-electrochemical performance and earth abundance. [21,22] However, there have been few applications of these materials to water electrolysis. To our knowledge, only Fe 0.5 V 0.5 composites, CoÀ V hydr(oxy)oxide, and NiÀ V double-layered hydroxides have shown high activity as OER catalysts. [23][24]...

In situ assembly of metal-organic framework-derived N-doped carbon/Co/CoP catalysts on carbon paper for water splitting in alkaline electrolytes

“…The overall water-splitting process consists of two parts: the oxygen evolution reaction (OER) for water oxidation and the hydrogen evolution reaction (HER) for proton reduction. The OER is the rate-determining step in water splitting; it involves the transfer of four electrons and is accompanied by the breakage of an O−H bond and the formation of an O-O bond [2,3]. Generally, HER catalysts operate under acidic conditions [4][5][6][7][8], whereas the OER is generally conducted in alkaline media [9][10][11][12][13].…”

Advances in Functional Ceramics for Water Splitting: A Comprehensive Review

“…The tunability of the band gap in these materials offers opportunities for optimizing their photocatalytic behavior, contributing to the development of efficient water-splitting technologies. Efforts to develop non-noble metal catalysts, such as V 4 P 6.98 /VO(PO 3 ) 2 , have been expended to address the challenge of achieving high activity for water splitting in alkaline media [107]. Furthermore, the design of hybrid bioinorganic systems presents a unique approach where the biological component utilizes reducing equivalents generated from water splitting for CO 2 fixation, leveraging the near-thermodynamic potential of biological catalysts [108].…”