Redox-Based Visible-Light-Driven Z-Scheme Overall Water Splitting with Apparent Quantum Efficiency Exceeding 10%

Abstract

A photocatalytic Z-scheme overall water-splitting system with unprecedentedly efficient apparent quantum efficiency of 10.3% at 420 nm is fabricated by using [Fe(CN) 6 ] 3À /[Fe(CN) 6 ] 4À as redox mediator. The metallic Au deposited is first demonstrated to highly favor the reduction of [Fe(CN) 6 ] 3À ions, and site-selective deposition of Au and CoO x makes a synergetic promotion on the charge separation and is responsible for greatly promoted O 2 evolution as well as overall water-splitting activity.

Water Oxidation Catalysts for Artificial Photosynthesis

“…Very recently, Zhang and co‐workers further updated the AQE record of Z‐scheme OWS up to 10.3% (λ = 420 nm) for the redox‐based Z‐scheme OWS systems by using Au/CoO x /BiVO 4 as the OEP and ZrO 2 /TaON as the HEP, and [Fe(CN) 6 ] 3− /[Fe(CN) 6 ] 4− as the redox mediator ( Figure a,b) . CoO x and Au nanoparticles as reduction and oxidation cocatalysts were selectively photodeposited on the {110} and {010} facets of BiVO 4 , respectively.…”

“…Schematic illustration for photocatalytic Z‐scheme overall water splitting and the time courses of gas production on the particulate a,b) BiVO 4 ‐ZrO 2 /TaON particles and c,d) the SrTiO 3 :La,Rh/Au/BiVO 4 :Mo photocatalyst sheet, respectively. b) Reproduced with permission . Copyright 2018, Elsevier.…”

Photocatalyst Z-scheme system composed of a linear conjugated polymer and BiVO4 for overall water splitting under visible light

“…As such, a number of research teams have investigated systems that mimic nature using a two-step excitation process for overall water splitting, typically by coupling together two different photocatalysts with a redox mediator to form a 'Zscheme'. [21][22][23][24] Most photocatalysts so far have been inorganic materials, but organic photocatalysts have attracted growing attention 25 because they can be prepared from earth-abundant elements and their properties-and in particular their light absorption spectrum-can be tuned easily and continuously by co-polymerisation. [26][27][28][29][30][31][32][33][34] However, most polymer studies have been conned to the sacricial half-reaction that produces hydrogen only, and few organic photocatalysts have been developed for overall water splitting.…”

A Step toward Economically Viable Solar Fuel Production

“…exciting that a record SOEE of 14.1% was achieved, which is 4.7 times higher than the previous leader (3.2%). 5 As presented in this work, besides the solar energy conversion efficiency of the photoelectrode, the match between the photovoltage of the photoelectrode and the potentials of redox-active materials can significantly affect the SOEE of the SFBs. To maximize the utilization of the harvested solar energy, the RFB cell voltage should be close to the effective photovoltage of the photoelectrode.…”