A TiO₂/FeMnP Core/Shell Nanorod Array Photoanode for Efficient Photoelectrochemical Oxygen Evolution

Abstract

A variety of catalysts have recently been developed for electrocatalytic oxygen evolution, but very few of them can be readily integrated with semiconducting light absorbers for photoelectrochemical or photocatalytic water splitting. Here, we demonstrate an efficient core/shell photoanode with a highly active oxygen evolution electrocatalyst shell (FeMnP) and semiconductor core (rutile TiO) for photoelectrochemical oxygen evolution reaction. Metal-organic chemical vapor deposition from a single-source precursor was used to ensure good contact between the FeMnP and the TiO. The TiO/FeMnP core/shell photoanode reaches the theoretical photocurrent density for rutile TiO of 1.8 mA cm at 1.23 V vs reversible hydrogen electrode under simulated 100 mW cm (1 sun) irradiation. The dramatic enhancement is a result of the synergistic effects of the high oxygen evolution reaction activity of FeMnP (delivering an overpotential of 300 mV with a Tafel slope of 65 mV dec in 1 M KOH) and the conductive interlayer between the surface active sites and semiconductor core which boosts the interfacial charge transfer and photocarrier collection. The facile fabrication of the TiO/FeMnP core/shell nanorod array photoanode offers a compelling strategy for preparing highly efficient photoelectrochemical solar energy conversion devices.

Rational Design and Construction of Cocatalysts for Semiconductor‐Based Photo‐Electrochemical Oxygen Evolution: A Comprehensive Review

“…With this method, Schipper et al [118] successfully synthesized an efficient TiO 2 /FeMnP core/shell photoanode for PEC water oxidation, which reached the theoretical photocurrent density for rutile TiO 2 of 1.8 mA cm −2 at 1.23 V RHE under 1 sun irradiation (Figure 10d). Confronted with it, researchers have made some efforts to tackle this bottom-neck.…”

“…Sci. [118] Copyright 2017, American Chemical Society. a) Charge separation and transfer mechanism in the C-Co-Pi/Fe 2 O 3 photoanode.…”

Component‐Tunable Rutile‐Anatase TiO2/Reduced Graphene Oxide Nanocomposites for Enhancement of Electrocatalytic Oxygen Evolution

“…So, an electron transfer mechanism is suggested (Figure ). The band gap of rutile and anatase TiO 2 is 3.0 eV and 3.2 eV, respectively ,. While, the energy of conduction band (bottom) of rutile is higher than that of anatase.…”

“…The obtained electrocatalysts exist in the form of rutile‐anatase TiO 2 /RGO nanocomposites in which the components of rutile and anatase can be tuned. Benefit from lower activation energy induced by the charge transfer between anatase and rutile, as well as TiO 2 and RGO, the optimized sample exhibits an overpotential as low as 283 mV at 10 mA cm −2 in 1 M KOH, which is superior to the reported TiO 2 (600 mV) and comparable with the leading results of other active materials ,,,,–,,, The fabrication of the rutile‐anatase/RGO nanocomposites with enhanced OER catalytic activity along with its mechanism investigation may offer a new alternative way for potential electrocatalysts.…”

Metal Phosphides as Co‐Catalysts for Photocatalytic and Photoelectrocatalytic Water Splitting

“…b) Current-voltage (J-V)c urves of TiO 2 nanorods and TiO 2 /FeMnPc ore/shell nanorod photoanodes in the dark and under irradiation.c)Band alignment of the described photoanode. Reproduced with permission from Ref [104]…”