**Author details**

deliberated. The polymer/inorganic metal oxide nanocomposite has been extensively used for the photodegradation of pollutants, ion exchanger, adsorbent, membrane, and photocatalytic disinfection in water treatment. For instance, polymer-based nanocomposites have several intrinsic importance such as high mechanical strength, long-term stability, and low-cost fabrication process, while the inorganic metal oxide possesses superior optical, electronic, magnetic, and catalytic properties. Thus, the hybridization of polymers and metal oxide could enhance several properties of the resultant nanocomposites. In conclusion, the polymer/metal oxide nanocomposite reviewed in this book chapter possesses superior photodegradation activity toward pollutants under simulated light irradiation owing to the large expose area of the nanocomposite, effective migration and separation of charge carriers as well as the strong electrostatic interaction between the catalyst and the pollutants. Moreover, the nanocomposite, exhibit high antibacterial activity, strong affinity toward ions owing to the strong electrostatic interactions between the positively charged ions of the inorganic metal oxide and the lone pair of the organic polymers, excellent regeneration, and adsorption performances, better antifouling property, excellent hydrophilicity due to porosity, larger surface pore size, less microvoids as well as good ion-exchange capacity. Though this book chapter is not a comprehensive, but can give a basic idea about polymer nanocomposites in the various water

Though considerable development in water treatment using metal oxide and polymer nanocomposite has been accomplished, studies in this area are still at the primary stage and additional advancement is essential. The design and fabrication of materials for water treatment process, particular visible light-response polymer/metal oxide–based photocatalyst materials are significant, but several reports briefly consider only the technical hurdles, high operating cost, and environmental risks. In future, to enhance the practicability of visible light response polymer/metal oxide–based photocatalyst materials in water treatment, several key issues, such as improving the photostability and efficiency of the photocatalyst materials need to be addressed. Moreover, the usage of photocatalytic materials in the photodegradation of pollutants is still a major issue considering the degradation and dissolution of the pollutants, which can hinder their photocatalytic performances. Hence, care should be taken when designing a functional polymer/metal oxide–based material with suitable physicochemical properties. Developing a suitable immobilization approach with cost-effective solid-liquid separation is also important. Currently, an exhausting catalyst during the photocatalysis process will endanger the regeneration of the catalysts and impacts severe effects on the environment as a result of catalysts outflow. To acquire an improved photodegradation efficiency, incorporating different techniques is essential. The accumulation of an enormous amount of theoretical study is also significant to prove an in-depth understanding of the preparation, performances, optimisation,

and properties of polymer/metal oxide–based photocatalysts for water treatment.

The authors would like to acknowledge the financial contributions from the Faculty of Science: the University of Johannesburg-South Africa, Centre for Nanomaterials and Science Research: Department of Applied Chemistry and the National Research Foundation (TTK14052167682).

treatment approaches.

188 Descriptive Inorganic Chemistry Researches of Metal Compounds

**Acknowledgements**

Francis Opoku, Ephraim M. Kiarii, Penny P. Govender and Messai Adenew Mamo\*

\*Address all correspondence to: messaim@uj.ac.za

Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa
