Construction of ultrafine Ag3PO4 nanoparticle and La2Ti2O7 nanosheet 0D/2D heterojunctions with improved photocatalytic performance

In this paper, we took the initiative to investigate the synthesis and photocatalytic properties of new solar-light active Ag3PO4/La2Ti2O7 0D/2D heterojunction photocatalysts with 10 wt% ∼70 wt% Ag3PO4 loading. 2D La2Ti2O7 nanosheets modified by uniformly dispersed super-small Ag3PO4 nanoparticles with average particle size as small as 4.9 nm were prepared by an in-situ chemical deposition method, and probed by electron microscopy, X-ray diffraction and UV–vis diffuse reflection spectroscopy. The photocatalytic activities were evaluated using Rhodamine B (RhB) as a target organic pollutant under simulated solar light irradiation. The results show that La2Ti2O7 nanosheets modified with proper amount of Ag3PO4 nanoparticles exhibited much higher photocatalytic activity. The optimal loading amount of Ag3PO4 was observed to be 50 wt% with the best photocatalytic performance, which could degrade almost all RhB dyes within 8 min under sunlight irradiation with the highest rate constant value of 0.5632 min−1. The mechanism accounting for the photocatalytic results were also proposed by PL, transient photocurrent response, radical trapping experiments and electron paramagnetic resonance spectra. Moreover, the photocorrosion of Ag3PO4/La2Ti2O7 photocatalysts is efficiently suppressed after depositing thin layers of AgI on Ag3PO4 nanoparticles.