Fig. 4

Investigation of the effect of carbon impurities in the CO2PR. a CH4 yield comparison of xPHTSO (x = 1.8, 3.4, 4.3, and 7.0) in different atmospheres, where blue bars denote the yield of CH4 generated from CO2/H2O atmosphere and gray bars denote the yield of CH4 generated from Ar/H2O atmosphere. b TEM images of 1.7Pt@PVP/HTSO and 1.7 nm Pt NPs colloidal (inset) the scale bars are 20 and 10 nm (inset), and c comparison of CO2 photoreduction evaluation over 1.7Pt@PVP/HTSO and 1.8PHTSO