Key Strategies on Cu2O Photocathodes toward Practical Photoelectrochemical Water Splitting

Abstract

Cuprous oxide (Cu2O) has been intensively in the limelight as a promising photocathode material for photoelectrochemical (PEC) water splitting. The state-of-the-art Cu2O photocathode consists of a back contact layer for transporting the holes, an overlayer for accelerating charge separation, a protection layer for prohibiting the photocorrosion, and a hydrogen evolution reaction (HER) catalyst for reducing the overpotential of HER, as well as a Cu2O layer for absorbing sunlight. In this review, the fundamentals and recent research progress on these components of efficient and durable Cu2O photocathodes are analyzed in detail. Furthermore, key strategies on the development of Cu2O photocathodes for the practical PEC water-splitting system are suggested. It provides the specific guidelines on the future research direction for the practical application of a PEC water-splitting system based on Cu2O photocathodes.

Facile Synthesis of Ni-MgO/CNT Nanocomposite for Hydrogen Evolution Reaction

“…This poses a significant environmental concern, as it contributes to the ever-increasing issue of greenhouse gas emissions, underscoring the pressing need for alternative and sustainable methods in hydrogen production to mitigate these adverse environmental impacts [3]. Over the past few decades, electrocatalytic water splitting was adopted by researchers as an effective technique for pure hydrogen production [4][5][6][7]. The electrocatalysis of water primarily consists of two half redox reactions: anodic oxygen evolution (OER), with a four-electron step transfer and cathodic hydrogen evolution reaction (HER), with a two-electron step transfer [5].…”

“…In those two steps, hydrogen generation proceeded depending on the process of adsorption (Volmer) and the desorption and recombination (Heyrovsky and Tafel) process of the adsorbed hydrogen (H*) and hydroxide ions (OH − ), which plays a vital role in H 2 generation and in high HER catalytic performance. To this date, noble catalysts such as Pt/C-or Ru/IrO 2 -based materials have exhibited outstanding electrocatalytic performances towards overall electrochemical water splitting [6][7][8][9][10]. Consequently, the expensive costs and instability of these worthy candidates severely limit their growth in industrial applications.…”