Mechanistic Insights for Photoelectrochemical Ethanol Oxidation on Black Gold Decorated Monoclinic Zirconia

Abstract

Surface decoration of metal oxides by metals for enhancing their electrocatalytic properties for organic conversions has attracted a lot of researchers’ interest due to their high abundancy, inexpensiveness, and high stability. In the present work, a process for the synthesis of black gold (BG) using a citrate assisted chemical route and m-ZrO2 by a hydrothermal method at 200 °C has been developed. Further, different concentrations of black gold are being used to decorate the surface of zirconia by exploitation of surface potential of zirconia and gold surfaces. The catalyst having 6 mol % concentration of black gold shows excellent electrocatalytic activity for ethanol oxidation with low oxidation peak potential (1.17 V) and high peak current density (8.54 mA cm–2). The current density ratio (j f /j b ) is also high (2.54) for this catalyst indicating its high tolerance toward poisoning by intermediate species generated during the catalytic cycle. The enhanced electrocatalytic activity can be attributed to the high tolerance of gold toward CO poisoning and high stability of the ZrO2 support. The black gold decorated zirconia catalyst showed enhanced activity during photoelectrochemical studies when the entire spectrum of light falls on the catalyst. Ultrafast transient studies demonstrated plasmonic excitation of metallic free electrons and subsequent charge separation in the black gold–ZrO2 heterointerface as the key factor for enhanced photoelectrocatalytic activity.

A Ni3V2O8@g-CN nanocomposite-based p-n heterojunction: mechanistic insights into photocatalytic activation of the inert C(sp3)–H bond

“…49 A peak potential was observed corresponding to the oxidation peak due to NVO loading in the nanocomposites. 48,50 This also shows that with an increase in the NVO concentration in composites, photocurrent density increases up to that of NVO-1@g-CN. Further loading results in diminishing photocurrent density.…”

Synthesis of Linear Black Gold Nanostructures Processable as Sunlight and Low‐Energy Light Collecting Films for Photo‐Thermoelectricity

“…It has been reported that small Au nanoparticles assemble to form black Au structures. [ 28–31 ] Highly branched superparticles are synthesized through the morphological modulation in the seeded growth process. [ 32 ] Porous or fibrous templates are used to deposit Au or Au nanoparticles through evaporation or wet chemical methods.…”

CFD modeling and simulation of benzyl alcohol oxidation coupled with hydrogen production in a continuous-flow photoelectrochemical reactor

“…The oxidation of biomass alcohols and their derivatives, e.g. ethanol 8 – 10 , glycerol 11 – 13 , glucose 14 – 16 , methanol 17 , 18 , and benzyl alcohol 3 , 6 , 7 , 19 , has been previously investigated to replace OER and promote hydrogen production via a photoelectrochemical process using various semiconductor electrode systems. However, the development of facile routes for transformation of alcohols remains a big challenge due to low conversion and selectivity, limited charge transport and reaction kinetics, and limited efficiency because of reactor design issues.…”