Interface-engineered Z-scheme of BiVO4/g-C3N4 photoanode for boosted photoelectrochemical water splitting and organic contaminant elimination under solar light. (December 2022)

• Record Type: Journal Article
• Authors: Mane, Pratik; Bae, Hyojung; Burungale, Vishal; Lee, Sang-Wha; Misra, Mrinmoy; Parbat, Harichandra; Kadam, Abhijit N.; Ha, Jun-Seok
• Is Part Of: Chemosphere. Volume 308:Part 1(2022)
• Publication Date: 2022-12
• Subjects: Bismuth vanadate -- Photoelectrochemical water splitting -- Water remediation -- Z-scheme -- Solar light; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.136166
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Although n-type bismuth vanadate (BiVO4 ) is regarded as an attractive solar-light-active photoanode, its short carrier-diffusion length, sluggish oxidation kinetics, low electronic conductivity, and high recombination rate are the major intrinsic shortcomings that limit its practical application. To this end, the rational design of a solar-light-active, metal-free BiVO4 -based Z-scheme heterojunction photoanode is of great significance for achieving effective charge-separation features and maximum light utilization as well as boosting redox activity for efficient environmental treatment and photoelectrochemical water splitting. Herein, we propose a facile approach for the decoration of metal-free graphitic carbon nitride (g-C3 N4 ) nanosheets on BiVO4 to form a Z-scheme BiVO4 /g-C3 N4 photoanode with boosted photoelectrochemical (PEC) water splitting and rapid photoelectrocatalytic degradation of methyl orange (MO) dye under simulated solar light. The successful preparation of the Z-scheme BiVO4 /g-C3 N4 photoanode was confirmed by comprehensive structural, morphological, and optical analyses. Compared with the moderate photocurrent density of bare BiVO4 (0.39 mA cm −2 ), the Z-scheme BiVO4 /g-C3 N4 photoanode yields a notable photocurrent density of 1.14 mA cm −2 at 1.23 V vs. RHE (≈3-fold higher) with the promising long-term stability of 5 h without any significant photo-corrosion. Moreover, the PEC dye-degradation studies revealed that the Z-scheme BiVO4 /g-C3 N4 photoanode successfully degraded MO (≈90%) in 75 min, signifying a 30% improvement over bare BiVO4 . This research paves the way for rational interface engineering of solar-light-active BiVO4 -based noble-metal-free Z-schemes for eco-friendly PEC water splitting and water remediation. Graphical abstract: Image 1 Highlights: Facile fabrication of noble metal free dual functional Z-scheme of BiVO4 /g-C3 N4 photoanode. Z-scheme BiVO4 /g-C3 N4 photoanode confirmed by structure, morphology, and optical studies. Z-scheme BiVO4 /g-C3 N4 photoanode shows 3-fold photocurrent density than bare BiVO4. Z-scheme BiVO4 /g-C3 N4 photoanode shows rapid degraded methyl orange (∼90%) in 75 min. The plausible photoelectrocatalytic mechanism for degradation and water splitting is proposed.