Rationally engineered BiVO4 micro-leaves as a bifunctional photocatalyst for highly durable solar water treatment and water splitting

• Published in: Journal of environmental chemical engineering 2022-02, Vol.10 (1), p.106946, Article 106946
• Main Authors: Mane, Pratik, Bagal, Indrajit V., Bae, Hyojung, Burungale, Vishal, Cha, An-Na, Ryu, Sang-Wan, Kang, Soon Hyung, Ha, Jun-Seok
• Format: Article
• Language: English
• Subjects: Bismuth vanadate; Micro-leaf-like morphology; Photocatalysis; Water splitting; Water treatment
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2021.106946

Recently, the use of monoclinic bismuth vanadate (BiVO4) as a visible light active catalyst has continued to increase, thus minimizing major issues such as fast recombination, poor carrier mobility, and sluggish oxidation kinetics has become an increasingly crucial issue. Accordingly, we report the fabrication of phase-engineered BiVO4 micro-leaves via the facile hydrothermal route and their utilization in solar-light-driven azo dye degradation and water splitting. Notably, low-temperature calcined BiVO4 micro-leaves exhibited a monoclinic–tetragonal isotype heterostructure crystal system with highly active (110) oxidative facets that significantly improved redox chemistry, whereas exposed (040) facets facilitated charge transport from monoclinic to tetragonal crystallites. Rationally phase-engineered and (110)/(040)-oriented BiVO4 micro-leaves (mt-BiVO4) presented efficient visible-light-assisted dye-degradation efficiencies (~94%) for water treatment with high durability. Moreover, the fabricated samples displayed dominant photochemical oxygen evolution rates of 1509.62 and 1214.04 μmol h–1 g–1 in an aqueous solution of FeCl3 and AgNO3, respectively. Our results suggest that synergistic effects of exposed reactive facets, dual-phase, and morphology engineering boosted the photocatalytic activity in BiVO4 and provided a promising approach for the development of a bifunctional photocatalyst in water treatment and water-splitting devices. [Display omitted] •Rationally engineered BiVO4 micro-leaves were synthesized via hydrothermal route.•(110)/(040) facets, mixed phase boosted the photocatalytic activities.•Mixed phase BiVO4 micro-leaves were utilized as a bifunctional photocatalyst.•Excellent water-remediation efficiency (~94%) for MB dye removal was obtained.•Dominant OER rate of 1509.62 μmol.hr−1gm−1 was achieved in aqueous FeCl3 system.