Journal of Materials Science, Vol.55, No.7, 2958-2966, 2020
LSPR-excited obvious hydrogen yield enhancement for TiO2:Er3+, Yb3+@W18O49 quasi-core/shell heterostructure
A favorable process that utilizing upconversion (UC) luminescence to enhance the photocatalytic property for H-2 evolution is designed. In this work, TiO2:Er3+, Yb3+ nanosheets (NTs) are synthesized through facile solvothermal method. With a 980-nm laser excitation, the UC luminescence bands at about 522, 546 and 625 nm separately corresponding to the energy-level transitions of H-2(11/2), S-4(3/2) -> I-4(15/2) and F-4(9/2) -> I-4(15/2) are detected in TiO2:Er3+, Yb3+ NTs, which coincide with the absorption band of W18O49 nano-urchins (NUs). It is worth noting that a quasi-core/shell heterostructure (QCSH) of TiO2:Er3+, Yb3+@W18O49 is designed and prepared as a photocatalyst on account of localized surface plasmon resonance action of W18O49. Photocurrent tests show TiO2:Er3+, Yb3+@W18O49 QCSHs possess outstanding charge separation ability comparing with W18O49 NUs and TiO2:Er3+, Yb3+ NTs under irradiation of 980-nm laser. Therefore, we probe photocatalytic property of H-2 evolution from ammonia borane (BH3NH3). The H-2 yield of TiO2:Er3+, Yb3+@W18O49 QCSHs suggests 2.5 times, 8.9 times and 26.6 times improved than that of W18O49 NUs, TiO2:Er3+, Yb3+ NTs and BH3NH3 separately. Furthermore, the focused natural sunlight is employed as excitation source, TiO2:Er3+, Yb3+@W18O49 QCSHs exhibits 1.7 times, 2.7 times and 157 times higher H-2 production than that of W18O49 NUs, TiO2:Er3+, Yb3+ NTs and BH3NH3, which offers a novel method for photocatalytic H-2 production and solving energy issues.