“…51,52 All diffraction peaks of the Nano Au/Ta 2 O 5 sample annealed at 650 C or higher temperature can be assigned exactly to the standard data of Ta 2 O 5 (JCPDS 25-0922). 53 Usually, a higher annealing temperature can signicantly improve the lattice integrity and crystallinity of the Nano Au/Ta 2 O 5 nanoarchitectures, which will optimize their photocatalytic activities for H 2 evolution accordingly. 50 The crystallite size of the samples can be estimated from the Scherrer equation, D ¼ 0.941l/b cos q, where D is the average grain size, l is the X-ray wavelength (0.15405 nm), and q and b are the diffraction angle and full-width at half-maximum of an observed peak, respectively.…”