A p‐n WO₃/SnSe₂ Heterojunction for Efficient Photo‐assisted Electrocatalysis of the Oxygen Evolution Reaction

Abstract

Water splitting is important to the conversion and storage of renewable energy, but slow kinetics of the oxygen evolution reaction (OER) greatly limits its utility. Here, under visible light illumination, the p‐n WO3/SnSe2 (WS) heterojunction significantly activates OER catalysis of CoFe‐layered double hydroxide (CF)/carbon nanotubes (CNTs). Specifically, the catalyst achieves an overpotential of 224 mV at 10 mA cm−2 and a small Tafel slope of 47 mV dec−1, superior to RuO2 and most previously reported transition metal‐based OER catalysts. The p‐n WS heterojunction shows strong light absorption to produce photogenerated carriers. The photogenerated holes are trapped by CF to suppresses the charge recombination and facilitate charge transfer, which accelerates OER kinetics and boost the activity for the OER. This work highlights the possibility of using heterojunctions to activate OER catalysis and advances the design of energy‐efficient catalysts for water oxidation systems using solar energy.

Photogenerated Carrier-Assisted Electrocatalysts for Efficient Water Splitting

“…In addition to designing photoelectric integrated catalysts, highly active electrocatalysts are also vital for the modification of photoactive species to enhance the efficiency of photogenerated carrier-assisted electrocatalysis. Lu et al prepared a p-n heterojunction structured material: p-n WO 3 /SnSe 2 [85]. The p-n heterojunction between WO 3 and SnSe 2 , with a small bandgap, can improve the high carrier recombination in the original WO 3 while enhancing its optical absorption ability.…”

Synergistic Coupling of Charge Extraction and Sinking in Cu5FeS4/Ni3S2@NF for Photoassisted Electrocatalytic Oxygen Evolution

“…22 For the OER, WO 3 /SnSe 2 , CoCr LDH, and NiOOH have been proved to have excellent P-EC activity, in which light irradiation can reduce the overpotential or increase the active sites, especially with the involvement of photogenerated holes. 15,23,24 However, the overall catalytic efficiency of P-EC under light illumination is still far below expected. 25 Specifically, previous works mainly focused on the construction of efficient bifunctional catalysts, whereas the effective extraction and utilization of photogenerated charge carriers of different components were not fully explored.…”

“…Recently, photoassisted electrocatalysis (P-EC) that fully utilizes solar energy to reduce electric energy consumption has gradually aroused great interest and been widely applied in several fields , such as the hydrogen evolution reaction, OER, carbon dioxide reduction, supercapacitors, and zinc-air batteries, in which the photogenerated charge carriers can efficiently enhance the intrinsic activity of the electrocatalysts. − P-EC mainly depends on the synergistic catalysis of the photo- and electroactive components . For the OER, WO 3 /SnSe 2 , CoCr LDH, and NiOOH have been proved to have excellent P-EC activity, in which light irradiation can reduce the overpotential or increase the active sites, especially with the involvement of photogenerated holes. ,, However, the overall catalytic efficiency of P-EC under light illumination is still far below expected . Specifically, previous works mainly focused on the construction of efficient bifunctional catalysts, whereas the effective extraction and utilization of photogenerated charge carriers of different components were not fully explored.…”

MoP4/Ni3S2/MoO3 heterogeneous structure nanorod arrays for efficient solar-enhanced overall water splitting

“…In addition, solar energy has gained widespread attention for use in clean, environmentally friendly, applicable and low-cost energy-assisted methods. For example, Bai et al 23 have synthesized the CoFe-LDH/WO 3 /SnSe 2 /CNTs composite material. Under visible light illumination, the overpotential required to attain a current density of 10 mA cm −2 is reduced from 291 mV to 224 mV.…”