Advances in thermocatalytic and photocatalytic techniques for the room/low temperature oxidative removal of formaldehyde in air

The skill for the proper management of air pollution turned out as one of the major concerns not only in the developed but also in developing countries. The materials used for the decoration of houses (e.g., wooden furniture, mats, and curtains) are often found to be major sources of highly dispersible light weight toxic air pollutants such as formaldehyde (FA) -well known for the priority carcinogenic substance. Although diverse remediation options (e.g., adsorbents, filters, and photocatalysts) are available to treat or remove FA, nano materials (NM)-based catalysts gained great attention due to several merits like enhanced degradation efficiencies, high regenerability, and favorable structural properties (e.g., high surface area and abundant surface hydroxyl group). Here, a comprehensive review is offered to describe the advanced NMs available for the catalytic degradation of FA based on thermocatalytic and photocatalytic approaches. In this review, nanomaterials developed for both catalytic methods have been evaluated critically for their degradation performances. Finally, the present shortcomings in the application of catalytic technologies toward either the maintenance or improvement of the indoor air quality have been discussed along with some prospective solutions and outlooks.