Photocatalytic H2 generation under blue and white LEDs by Fe2O3 /KTLO/rGO S-scheme composite photocatalyst

Abstract

Photocatalytic water splitting using LED is of feasible approach for renewable energy enlargement. Alkali-titanates decorated with iron oxide at the molecular level was designed by a solvothermal reaction between prepared graphene oxide and K0.8Li0.27Ti1.73O4 with Fe (III) chloride. The reduced graphene oxide with iron oxide on alkali-titanates extends the effective way for its visible light harvesting. The effect of α-Fe2O3 loading on K0.8Li0.27Ti1.73O4/rGO was investigated towards photocatalytic water splitting, and achieving an improved H2-production rate. This present study will propose a new insight into the design and fabrication of layered titanate graphene-based photocatalysts using inexpensive α-Fe2O3 as a co-catalyst. The α-Fe2O3-K0.8Li0.27Ti1.73O4/rGO photocatalysts were characterized well by powder XRD, FT-IR, Raman spectroscopy, FESEM/EDS, High-resolution TEM, XPS, UV-DRS, and PL studies. Combining of heterostructured alkali-titanate photocatalyst leads broadening in optical absorption with a shift in the energy potential with acceleration in the interfacial charge transfer between α-Fe2O3 and KTLO, and rGO enhanced charge separation efficiency with remarkable hydrogen production rate. KTLO/rGO/Fe/5% (6200 µmol g−1) presents an improved hydrogen evolution rate around 29.5 times higher than bare KTLO (210 μmol g−1). A possible photocatalytic mechanism was proposed to elucidate better hydrogen production by using lactic acid as a sacrificial agent.