Synthesis of NiO-PVA nanocomposite by laser assisted-method and its characterization as a novel adsorbent for removal phosphate from aqueous water

A laser ablation in liquid approach was used to generate nickel oxide nanoparticles (NiO NPs) dispersed in liquid media from a PVA solution to be applicable for the removal of phosphate from an aqueous solution. With a nanosecond Nd:YAG pulsed laser operating at 1064 nm, NiO NPs were produced and embedded in a matrix structure of PVA. Different approaches were used to investigate their structure, optical properties, and morphology. It was discovered that the NiO NPs were equally spread and fixed in the PVA cross-linked network structure. The main characteristic vibrational peaks of the PVA structure are developed in their intensity or locations. The new absorption peak appeared at around 270 nm due to the electronic transition from the inner levels of NiO to the fermi level of the empty conduction band based on doping the PVA structure with NiO NPs. After that, the effects of adsorption time, reaction temperature, pH, initial concentration of phosphate, and loading rate were investigated to get the optimum condition for the adsorption process to remove phosphate from an aqueous solution. It is concluded that PVA-NiO nanocomposite, prepared with 30 min of laser ablation, appears to be a promising adsorbent for removing phosphate at a 150 mg/L concentration from aqueous solution at pH 4.