Mesoporous BiVO₄/TiO₂ heterojunction: enhanced photoabsorption and photocatalytic ability through promoted charge...

BiVO₄ has been constructed into heterojunctions with TiO₂ to boost the photocatalytic ability under visible illumination. Here, mesoporous BiVO₄/TiO₂ nanocomposites have been fabricated by a facile sol-gel approach utilizing nonionic surfactant and addressed for morphological, optical, structural, and degradation of ciprofloxacin (CIP) in water under visible illumination as an antibiotic pollutant model. The TEM images demonstrated that the TiO₂ NPs are homogenous in terms of shape and size (15 ± 5 nm). The introduction of BiVO₄ into mesoporous TiO₂ could effectively enhance the rapid separation efficiency of the photoinduced carriers and optical absorption. The 3%BiVO₄/TiO₂ photocatalyst possessed the best degradation efficiency (100%) within 60 min which was promoted 20-folds larger than TiO₂ NPs (5%). 3%BiVO₄/TiO₂ nanocomposite exhibited the fastest degradation rate (2.15 × 10^-2 min^-1), which was 40 times faster than bare TiO₂ photocatalyst (0.05 × 10^-2 min^-1). The enhanced photocatalytic ability originated from superior charge separation characteristics and high solar energy absorption in mesopore structures. The recombination rate and mobility of charge carriers were characterized utilizing photoluminescence (PL) and photoelectrochemical measurements. This work highlights the advantages of mesoporous heterojunction BiVO₄/TiO₂ nanocomposites for photocatalytic performances and provides a multilateral route to design an effective wide-spectrum response photocatalyst for the development of comparable materials. The photocatalytic mechanism for degradation CIP over BiVO₄/TiO₂ was discussed in detail..