SiC-g-C3N4-TiCN photocatalysts for the solar photocatalytic H2 evolution from plastics photoreforming

The solar photoreforming of some plastic materials (polylactic acid from biodegradable glasses, polystyrene from food dishes and low-density polyethylene from food packaging) to obtain H2, were investigated employing an unusual photocatalytic composite made by SiC-graphitic carbon nitride (g-C3N4) and the titanium carbonitride (TiCN). The plastic materials were pre-treated in alkaline mild conditions to favour their depolymerization. Among the investigated reactions, the solar photoreforming of polystyrene led to obtain the highest H2 production rate (371 mu molH2/gcat center dot h) using the SiC-1 wt% g-C3N4-5 wt% TiCN. The presence of graphitic carbon nitride favoured the photoelectrons mobility, generated by the absorption of the solar light by the SiC, whereas the interaction with the titanium carbonitride strongly enhanced the charge carriers separation. With this unconventional photocatalyst composite it is possible to valorise the plastics waste in a sustainable way, producing at the same time a high added value product fuel as hydrogen with a green waste-to-fuel approach.