silver phosphate, also known as silver orthophosphate, is a light sensitive, yellow compound composed of silver and phosphate ions. It is soluble in dilute acetic acid and freely soluble in dilute ammonia, ammonium carbonate, alkali cyanides and thiosulfates. It is widely used in the photography industry as an emulsion for collodion emulsions and in medicine as a bactericide, antibacterial and antidiabetic agent.
silver phosphate as a Photocatalyst
To evaluate the photocatalytic activity of a silver phosphate coating, degradation experiments were conducted using methylene blue under a blue LED light source. A glass substrate coated with Ag3PO4 was placed in 50 mL of a 20 mg L-1 methylene blue solution, and was then irradiated by a blue LED light source. The concentration of methylene blue was then measured at regular intervals.
XRD patterns for raw silver phosphate, silver phosphate paste calcined at 300 degC and 500 degC and the composition ratio for the samples (1.0:1.0:0.030; Ag3PO4:H2O:CMC-Na) are presented in Fig. 7. Compared to the dried sample, a stronger diffraction peak for elemental silver was observed in both the 300 and 500 degC calcined samples when CMC-Na was added.
XRD results showed that the silver phosphate was recombined with CMC-Na during calcination. The XRD pattern of the silver phosphate paste was in good agreement with the diffraction data for the bare silver phosphate. The XRD pattern for the paste containing CMC-Na shows an intense diffraction peak for elemental silver at 38deg. This reflects the fact that silver phosphate recombined with CMC-Na to form elemental silver.