Hydrochar from orange peel waste and Black Mass from Spent Li-batteries as co-catalyts of C3N4 for H2 generation form aqueous solutions of organics

In this work g-C3N4 was enriched with a metal-based co-catalyst obtained from the cathodic part of s-LiBs, the black mass (BM) and also with hydrochar (HC) obtained via hydrothermal combustion of orange peel waste. A set of composites have been prepared by different strategies to obtain various g-C3N4/BM/HC photocatalysts. The amount of BM and HC, both bare or activated by different strategies, with respect to the precursor of C3N4 (melamine, thiourea or dycianamide) was fixed in the range 0.5 to 2 % w/w. The composites were tested for H2 production by photo reforming of organic aqueous solutions irradiated under UV LED 365 nm and solar light. Aqueous solutions of organics as ethanol, glycerol, triethanolamine or aqueous solutions obtained from the distillation of orange peel or during the preparation of the hydrochar from the biomass waste, were used as hole scavengers in the photoreforming process. The presence of BM enhanced the g-C3N4 activity for H2 obtainment and the presence of small amounts of HC furtherly improved the H2 productivity.