Abstract:
Herein, a Pd nanoparticle-embedded SBVCN-37 heterostructure photocatalyst was synthesized and
employed in the water-splitting reaction and for the synthesis of imines via a one-pot tandem reaction
involving the photocatalytic reduction of nitrobenzene and oxidation of benzyl alcohol, followed by their
condensation reaction. The embedded Pd nanoparticles (mean diameter 5–7 nm) act as an electron
mediator and enhance the catalytic activity of SBVCN-37 during the oxidation and reduction reactions.
The experimental results confirm that the light-induced holes owing to the favourable redox potential of
the catalyst oxidize N2H4 to N2 and liberate H+ ions, which subsequently react with photogenerated
electrons to facilitate the reduction of nitrobenzene. The obtained quantum yields for benzyl alcohol
oxidation and nitrobenzene reduction were calculated to be 2.08% and 6.53% at l ¼ 420 nm light
illumination, respectively. Furthermore, the obtained apparent quantum yields for the OER and HER were
calculated to be 10.22% and 12.72% at 420 nm, respectively, indicating the excellent potential of the
investigated photocatalyst for solar fuel production. Photoelectrochemical (PEC) and time-resolved and
steady-state photoluminescence measurements reveal that the optimum amount of Pd nanoparticles
over SBVCN-37 is the crucial factor for achieving the highest photocurrent response, lowest charge
transfer resistance, and efficient carrier mobility, leading to prominent catalytic activity. Furthermore, the
Mott–Schottky (M–S) analysis confirmed that the deposition of Pd nanoparticles effectively reduced the
over-potential and fine-tuned the band edge potential required for the HER and OER reactions,
respectively
