An Oxygen‐Insensitive Hydrogen Evolution Catalyst Coated by a Molybdenum‐Based Layer for Overall Water Splitting

Abstract

For overall water-splitting systems, it is essential to establish O -insensitive cathodes that allow cogeneration of H and O . An acid-tolerant electrocatalyst is described, which employs a Mo-coating on a metal surface to achieve selective H evolution in the presence of O . In operando X-ray absorption spectroscopy identified reduced Pt covered with an amorphous molybdenum oxyhydroxide hydrate with a local structural order composed of polyanionic trimeric units of molybdenum(IV). The Mo layer likely hinders O gas permeation, impeding contact with active Pt. Photocatalytic overall water splitting proceeded using MoO /Pt/SrTiO with inhibited water formation from H and O , which is the prevailing back reaction on the bare Pt/SrTiO photocatalyst. The Mo coating was stable in acidic media for multiple hours of overall water splitting by membraneless electrolysis and photocatalysis.

Aerobic Conditions Enhance the Photocatalytic Stability of CdS/CdOx Quantum Dots

“…[1] Alternatively,t his reactionc an be undertaken through the oxidation of organic species, either in the form of biomass-derived substrates,s uch as EtOH, MeOH,g lucoseo rl ignocellulose, [2][3][4] or throughs elective organic oxidation reactions to generate higher-value products. For example, deposition of thin layers of metal oxides, such as Cr 2 O 3 and SiO x /TiO x , [15,16] on the surface of a proton reduction catalyst can selectively preventd iffusion of O 2 to the catalyst, albeit under low levels of O 2 (< 1a tm of pressure).Previously reported systems have shown that proton reduction catalysts fall into two groups:O 2 sensitive, where ac atalyst is irreversibly damaged by O 2 ,o rO 2 tolerant, where ac atalyst is able to function under O 2 ,b ut at ar educed rate (Scheme 1). [6,7] Due to the ubiquity of O 2 in the atmosphere,a sw ell as its production in the water-splitting reaction, ap roton-reduction catalystm ust be ablet ot olerate its presence during activity.…”

“…[8][9][10] To date, little research has considered the effect of O 2 on semiconductor-driven H 2 evolution ando nly few reports are availableo nO 2 -tolerantm olecular proton-reduction catalysis. For example, deposition of thin layers of metal oxides, such as Cr 2 O 3 and SiO x /TiO x , [15,16] on the surface of a proton reduction catalyst can selectively preventd iffusion of O 2 to the catalyst, albeit under low levels of O 2 (< 1a tm of pressure). For example, deposition of thin layers of metal oxides, such as Cr 2 O 3 and SiO x /TiO x , [15,16] on the surface of a proton reduction catalyst can selectively preventd iffusion of O 2 to the catalyst, albeit under low levels of O 2 (< 1a tm of pressure).…”

Single Atoms on Graphene for Energy Storage and Conversion

“…To accelerate the kinetics of OER or HER process, various single atoms on carbon materials have been fabricated . However, it is still difficult to realize the good electrocatalytic performance in an integrated electrode for the simultaneous formation of H 2 and O 2 due to the different reaction mechanism . Therefore, the bifunctional catalysts on graphene that can be utilized in wide pH ranges are necessary to achieve the catalytic activity in water splitting.…”

Photocatalytic Oxygen Evolution from Functional Triazine‐Based Polymers with Tunable Band Structures

“…[1] Conjugated polymers present some advantages in terms of their sustainability,cost effectiveness, processability,and tunable properties,w hich can be adjusted with versatile organic protocols. To achieve this mission, conjugated polymers with semiconductor properties have recently been introduced to photocatalyze water splitting to complement inorganic semiconductors,which have been intensively investigated for 40 years.…”

“…To achieve this mission, conjugated polymers with semiconductor properties have recently been introduced to photocatalyze water splitting to complement inorganic semiconductors,which have been intensively investigated for 40 years. [1] Conjugated polymers present some advantages in terms of their sustainability,cost effectiveness, processability,and tunable properties,w hich can be adjusted with versatile organic protocols. [2] Indeed, conjugated polymers are gaining alot of interest owing to their optoelectronic properties and applications in plastic electronics while their use in artificial photosynthesis is still rare.…”