Diffusion controlled porous WO₃ thin film photoanodes for efficient solar-driven photoelectrochemical permanganic acid production

Abstract

Photoelectrochemical (PEC) oxidation of the divalent manganese ion to the permanganate ion was achieved by using porous WO3 thin film photoanodes in sulfuric acid electrolytes under simulated sunlight.

Acid-Resistant BiVO4 Photoanodes: Insolubility Control by Solvents and Weak W Diffusion in the Lattice

“…For the PEC reaction tests under simulated sunlight illumination, we prepared the bottom WO 3 layer using a nanoparticle deposition method reported elsewhere. ,, The prepared WO 3 nanoparticle dispersion (see the Supporting Information) was spin-coated at 2000 rpm for 10 s onto the F-doped SnO 2 (FTO) substrates, and the precursor films were preheated at 500 °C for 30 min in air. The spin-coating and preheating sequence was repeated twice, and the preheated films were subsequently heated at 550 °C in air for 30 min.…”

“…Promoting solar energy utilization is a primary challenge for researchers to solve several imminent issues, such as global warming and resource depletion. − The production of clean molecular fuels and high-value-added chemicals using semiconductor photoelectrodes is one of the attractive applications of solar light. − Numerous semiconductor photoelectrodes have been reported over the past two decades. , Among them, bismuth vanadate (BiVO 4 ) is a very promising photoanode for solar energy conversion in terms of its optical absorption, which has good compatibility with the solar spectrum. − BiVO 4 has a 2.4 eV band gap, and its valence-band edge is sufficiently positive for photoelectrochemical (PEC) oxidation reactions of various chemicals. ,, High photocurrent densities of ∼3.9 mA·cm –2 at 1.23 V RHE (vs reversible hydrogen electrode, RHE) have already been realized with preferentially [001]-oriented BiVO 4 (monolayer cell) for the PEC water oxidation reaction . In addition, some modification techniques such as multilayering and cocatalysts have been found to enhance the photocurrent of BiVO 4 .…”

Solar‐Driven Co‐Production of Hydrogen and Value‐Add Conductive Polyaniline Polymer

“…For this purpose, several schemes (Table S1, Supporting Information) have been reported using oxide semiconductor photoanodes to produce high-value chemicals [6][7][8][9] during H 2 production at the cathode. The products include hydrogen peroxide (H 2 O 2 ), [10][11][12] peroxydisulfate (S 2 O 8 2− ), [13][14][15][16] hypochlorite (ClO − ), [14,[17][18][19][20] Ce 4+ , [14,16] Cr 6+ , [21] Mn 7+ , [22] and 2,5-furandicarboxylic acid (FDCA). [6,23] Out of these listed work, WO 3 was regularly used as a photo-anode in the polycrystalline [14] form or as a sponge.…”

“…While H 2 gas was also produced at the same time for all of these processes, in some cases, positive potentials higher than 1.23 V used in conventional water splitting for the OER are required. [6,21] In many of these processes [10][11][12][13][14][15][16][17][18][20][21][22][23] , separators need to be used to avoid the diffusion of the products from the anodic and cathodic compartments to inhibit anodic products from being reduced at the cathode. Last, when anodic products are generated and dissolved in the electrolytes, collection and purification of these products are challenging representing barriers to low-cost and large-scale production.…”

Solar-to-Pharmaceutical Raw Material Production: Photoelectrochemical Naphthoquinone Formation Using Stabilized BiVO4 Photoanodes in Acid Media

“…Using solar energy is our priority challenge to solve severe environmental issues like global warming and resource depletion. − In the continued international efforts to achieve a 100% renewable energy scenario by 2050 envisioned by the World Wide Fund for Nature, global solar energy utilization has grown 10-fold in the last 10 years. , The use of solar energy has been intensely pressed forward, especially with advances in producing solar hydrogen and high-value-added chemicals such as hydrogen peroxide, peroxydisulfate ion, and hypochlorous acid semiconductor photoelectrodes is one of the most attractive uses of solar light. − The effective use of photoelectrochemical (PEC) anode reactions has reinforced the value of solar energy. Among the various semiconducting photoelectrodes reported in the last two decades, bismuth vanadate (BiVO 4 ) has emerged as a very promising photoanode for solar energy conversion.…”