Enhanced BiVO4 photocatalyst anchored on construction waste bricks powder for efficient formaldehyde and methylene blue degradation

With the increasing accumulation of construction waste and organic pollutants , efficient treatment methods are urgently needed. This study reports the hybridisation of construction waste bricks (CWB) with BiVO 4 (BVO) using a hydrothermal method to synthesise a novel photocatalytic material. Significant improvements in photocatalytic performance of the BVO/CWB-11 composite are seen to address charge carrier recombination in BVO. With a lower E g of 2.18 eV and an absorption edge extending to 577 nm, this composite can enhance visible light absorption and suppress electron hole recombination . The evidence for this includes reduced photoluminescence intensity showing the longer carrier lifetime and also the enhanced transient photocurrent response. Under simulated visible light, BVO/CWB-11 gives degradation efficiencies for methylene blue (MB) and formaldehyde (CH 2 O) of 95.66 and 77.85 %, respectively, which are 1.8 and 1.37 times that of pure BVO. The incorporation of CWB not only provides a low-cost recycling option for construction waste but also offers an alternative approach to the treatment of MB and CH 2 O removal. This work provides a stepping stone towards the application of BVO-based photocatalysts in environmental remediation. • BVO/CWB-x composites significantly boosted methylene blue and formaldehyde degradation under visible light. • A type-II heterojunction between monoclinic and tetragonal BVO suppressed electron–hole recombination. • Fe 3 + doping narrowed the band gap and enhanced charge separation. • SiO 2 from CWB formed interfacial heterojunctions, improving electron conduction pathways. • The synergistic effects of heterojunctions and Fe 3+ doping greatly enhanced photocatalytic efficiency and stability.