A novel p–n junction Ag₃PO₄/BiPO₄-based stabilized Pickering emulsion for highly efficient photocatalysis

Abstract

This study demonstrates a new kind of photocatalytic system via utilization of the superior specific properties inherent in Pickering emulsions.

Synthesis of Surface Oxygen-deficient BiPO4 Nanocubes with Enhanced Visible Light Induced Photocatalytic Activity

“…As investigated from Figure 4b the intensity of the EPR signal at g ~ 2.001 of GBiPO 4 is much higher than that of WBiPO 4 under the same conditions. As reported previously, g equal to 2.003 ± 0.001 can be attributed to oxygen vacancies on the surface 18,19,25 indicating that surface oxygen vacancies were produced on GBiPO 4 .…”

“…Figure 1 shows SEM images of WBiPO 4 and GBiPO 4 . It is clearly seen that the as synthesized WBiPO 4 had a cuboid-like shape with a smooth surface and clear edges (Figure 1a).…”

“…The discrepancy always makes the highly photocatalytic efficient photocatalyst less visible light response. For instance, BiPO 4 , with a novel nonmetal oxy-acid salt structure, has the suitable VB and CB position for highly photocatalytic performance which showed twice higher activity than that of TiO 2 (P25, Degussa) for the degradation of organic dye under UV light 9 . However, the large band gap energy of BiPO 4 (3.85 eV) prevented it from utilizing the visible light to meet the requirement of practical application 10,11 .…”

“…However, the large band gap energy of BiPO 4 (3.85 eV) prevented it from utilizing the visible light to meet the requirement of practical application 10,11 . Therefore, great efforts have been made to broaden the visible light absorption region and obtain high visible light induced photocatalytic performance of BiPO 4 . As is known coupling of a narrow band gap semiconductor such as CdS 12 , BiOI 13 and Ag 3 PO 4 14 on the BiPO 4 surface to form the p-n heterojunctions can increase the visible light induced photocatalytic activities of the catalyst.…”

“…Photocatalysis has attracted considerable attention ever since the photocatalytic splitting of water on TiO 2 electrodes was investigated by Fujishima and Honda 1 , which provides a new promising way to meet the challenges of the environment, energy and sustainability with abundant solar light [2][3][4] . Although TiO 2 is the most promising photocatalyst and is widely investigated due to its non-toxicity, chemical stability and low cost, low solar energy conversion efficiency and high recombination of photogenerated electron-hole pairs make it difficult for practical applications 5,6 .…”