Oxidative removal of phenol from water catalyzed by nickel hydroxide

This work explores the preparation and characterization of nickel hydroxide catalyst and investigation of its catalytic activities for oxidative degradation of phenol in aqueous medium using batch reactor. The catalyst was prepared by reaction of sodium hypochlorite, sodium hydroxide and nickel sulfate hexahydrate in distilled water. The prepared catalyst was characterized by surface area, particle size, FTIR, XRD, SEM, and determination of oxygen content measurements. The prepared nickel hydroxide was used as catalyst for oxidative degradation of phenol in aqueous medium by taking 15 mL of 0.71 M phenol solution. The catalytic performance of nickel hydroxide was explored in terms of effect of time, temperature, partial pressure of oxygen, initial concentration of phenol, catalyst loading and effect of stirring speed on degradation of phenol. The catalyst was separated from the reaction mixture by filtration. Langmuir–Hinshelwood type of mechanism was followed in the reaction where adsorption of phenol and oxygen at the surface of catalyst was taking place according to competitive Langmuir and Temkin adsorption isotherm, respectively.

Graphical abstractKinetic expression for oxidative degradation of phenol in aqueous medium catalyzed by nickel hydroxide.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Preparation of nickel hydroxide catalyst. ► Characterization of the catalyst by various techniques. ► Catalytic efficiency of nickel hydroxide for oxidative degradation of phenol. ► Effect of various parameters on catalytic degradation of phenol. ► Heterogeneous kinetics of oxidative degradation of phenol.