Highly efficient visible-light driven photocatalytic hydrogen evolution over Er3+:YAlO3/Ta2O5/rGO/MoSe2 nanocomposite

Here, a novel coated composite, Er3+:YAlO3/Ta2O5/rGO/MoSe2, was successfully prepared by sol-hydrothermal and calcination methods, in which the MoSe2 and reduced graphene oxide (rGO) hybrids as co-catalyst were used to act as the electron collector and active reaction sites. Er3+:YAlO3, MoSe2/rGO, Er3+:YAlO3/Ta2O5 and Er3+:YAlO3/Ta2O5/rGO/MoSe2 were all characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Raman spectrum, UV-vis diffuse reflectance spectra (DRS) and transmission electron microscopy (TEM). UV-vis absorption and photoluminescence (PL) spectra of Er3+:YAlO3 were also measured. The photocatalytic hydrogen production activity of Er3+:YAlO3/Ta2O5/rGO/MoSe2 was examined under visible-light irradiation. The main influence factors such as initial solution pH and mass ratio of Ta2O5 and MoSe2/rGO on visible-light photocatalytic hydrogen production activity of Er3+:YAlO3/Ta2O5/rGO/MoSe2 were discussed in detail. The results showed that the coated composite (Er3+:YAlO3/Ta2O5/rGO/MoSe2) with 99.25:0.75 mass ratio of Ta2O5 and MoSe2/rGO in methanol aqueous solution at pH = 6.00 could display the highest photocatalytic hydrogen production activity. Furthermore, a high level of photocatalytic activity can be still maintained within five cycles under the same conditions. It implies that the novel coated composite, Er3+:YAlO3/Ta2O5/rGO/MoSe2, may be a promising photocatalyst utilizing solar energy for hydrogen production.