LAUSR

Abstract The Zn0.3Mn0.4O4 Nanospheres (ZnMnONs) were synthesized for the photocatalytic reduction of CO2 to CH4. The average particle size was 70.1 nm and having composition of Zn, Mn and O are about 18.93, 21.30 and 59.77 wt% respectively. The catalysts were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), IR spectra and UV–vis spectrophotometer. Zn0.3Mn0.4O4 is used for efficient photocatalytic CO2 to methane which is an important component in a future sustainable post carbon energy system. It was reached to 2.65 μmol/g of CH4 yield, and the photocatalyst presented a potential for reducing CO2 emission. The recovered nanospheres sample from methane production is further used for phosphate adsorption for exploring its multifunction application. The maximum% adsorption observed at 200 mg of adsorbent concentration at 40 min of agitation time. The adsorption study follows the first order of kinetics, Langmuir isotherm graph deduced the qmax value at 125 mg/g & Freundlich equilibrium isotherm also shows the linear plot. The essential features of the Langmuir isotherm can be expressed in terms of a dimensionless constant called separation factor. The value of RL indicates the shape of the isotherms to be either unfavorable (RL > 1), linear (RL = 1), favorable (0