statistical modeling of p-nitrophenol degradation using a response surface methodology (rsm) over nano zero-valent iron-modified degussa p25-tio2/zno photocatalyst with persulfate

Zero-valent iron-modified degussa p25-tio2/zno nanocomposites (denoted as p25/fe0/zno) were designed and prepared via fe0 impregnation of p25-tio2/zno and then were employed in the visible-light photocatalytic degradation of p-nitrophenol (pnp) in the presence of [k2s2o8]. central composite design was applied for response surface modeling (rsm) to understand the influence of selected factors (ph, [fe0] wt% and [k2s2o8] concentration) on the degradation of pnp and to determine the interaction between the factors. the maximal pnp degradation efficiency (86.9%) was obtained with p25/1.5 wt% fe0/zno at 3 mg/l of [k2s2o8] concentration and ph 7.5. in addition, the rsm showed a satisfactory correlation between the experimental and predicted values of pnp degradation. the p25/fe0/zno photocatalyst performance was also examined degrading methyl orange and phenol and high degradation efficiency, 82 and 99%, was achieved, respectively. the structure, morphology, light absorption and photocatalytic properties of as-prepared p25/fe0/zno were studied using tem, bet, xrd, ftir and drs.