Investigation of hexanal removal through adsorption and photocatalysis on ZIF-7 modified with ZnO, TiO\(_2\), and ZnO/TiO\(_2\) using ATR-FTIR

Zeolitic imidazolate framework (ZIF) is renowned for its high adsorption capacity and frequently adsorbs organic pollutants. However, its high band gap energy has limited its photocatalytic activity, thus necessitating a modification for enhance performance enhancement. This study focuses on developing a ZIF-7 composite material that integrates adsorption and photocatalysis to remove volatile organic compounds (VOCs), particularly hexanal. Modifications were made by incorporating ZnO, TiO2, and ZnO/TiO2 via a solvothermal method using dimethylformamide (DMF). ATR-FTIR analysis was employed to monitor any changes in peak intensity related to the C=O vibrations of hexanal around 1700 cm-1. The results showed that all samples effectively adsorbed hexanal, reducing peak intensity after UV irradiation, and confirming successful photocatalysis. Notably, TiO2@ZIF-7 exhibited the highest photocatalytic performance with 88.06% degradation efficiency. This study confirms that the ATR-FTIR method can be used to monitor the success of adsorption and photocatalysis and shows the potential for developing composite materials to remove VOCs such as hexanal.