Bi-functional V₂O₅ nanorods loaded biomass-derived activated carbon nanocomposites for enhanced photocatalytic dye degradation and hydrogen production

Activated carbon (AC) was synthesized from hemp-derived biochar (BC) as a precursor, by chemical activation procedure, using KOH as an activating agent. Different compositions of nanorod V₂O₅ (5, 10, and 15 wt%) structures were loaded on AC carrier and various characterization techniques were employed to investigate the physicochemical and photocatalytic performance of as-synthesized catalysts in dye degradation and H₂ production. Under exposure to sunlight, different loadings of 5 %, 10 %, and 15 % of V₂O₅@AC nanocomposites were used for the crystal violet (CV) photocatalytic dye degradation. Amongst all compositions, 5 % V₂O₅@AC shows maximal degradation efficiency of up to 99 % and it is the suitable candidate for the degradation of dyes, where superoxide radicals (*O₂⁻) play an essential role in CV degradation during active radical trap test. Furthermore, photocatalytic H₂ production was performed in a slurry-based reactor system. The results demonstrate an enhanced H₂ production rate (∼889 μmol g⁻¹ h⁻¹ in 180 min), due to optimal photocatalytic performance of 5 % V₂O₅@AC. The presence of an intraband gap in the case of 5 % V₂O₅@AC suggests the presence of oxygen vacancies in the lattice, that contribute to the photocatalytic performance by providing an alternative energy path - thus maximum light is absorbed, ranging from visible to ultraviolet spectrum, which that will ultimately contribute to efficient electron transition and separation, despite having wide bandgap.