A review on recent developments in structural modification of TiO2 for food packaging applications

Structural modification of titanium dioxide has offered a novel template to develop advanced functional materials which demonstrate visible light photocatalytic activity. There had been many attempts to modify the band gap of TiO₂ in order to realize its potential as an antimicrobial material in food coatings and packaging. This review gathers most recent advancements of developing TiO₂ based functional nanohybrids which include doping with metals, non-metals, co-doping, and development of hybrids with 2-D nanomaterials. In particular, nanohybrids prepared with of TiO₂ with graphene incorporation has opened up a novel platform to reduce the band gap while minimizing the inherent drawback of electron pair recombination in TiO₂. In this review, critical analysis of the recent literature on the mechanisms involved in structural modifications are discussed broadly and the electronic and functional properties of resulting materials are presented with a greater scientific depth. In addition, the available structural modification techniques have been compared with a particular emphasis on food preservation and post-harvest loss mitigation applications. More importantly, an outlook on the industrial applications, future directions and challenges have been suggested and discussed.