We have reported the first example of floating photocatalysts for application to up-scaled photoreforming of model and waste substrates using both Pt and a noble-metal-free co-catalyst. HGM/CNx|Pt and HGM/CNx|Ni2P composites, where the role of the HGMs is as an inert lowdensity support conferring floatation in water, were prepared by a simple pyrolysis procedure followed by thermal or chemical reduction to deposit the co-catalyst. Such floating composites and devices for solar fuel production enable versatile deployment scenarios, such as in turbid waste streams or on open waters, in addition to their advantages in terms of recyclability and scalability. Composite preparation and application conditions were optimised for H2 production and shown to generate H2 gas when coupled with ethylene glycol, pre-treated PET, and pretreated cellulose. The floating composite was evaluated at small (5 mL, 4.9 cm 2 ) and large (217 mL, 217 cm 2 ; to the best of our knowledge, the largest areal scale PR system reported in the literature to date) scales under vertical solar irradiation to simulate realistic application conditions, and it was found that PR activity could be maintained over up to 10 cycles (2 h per cycle). Estimated continuous catalyst reuse for scaled practical photoreforming is >1 year, necessitating long term evaluation of this composite in continuously operating systems before floating catalysts can be considered a solution to reuse, though the development of this floating platform is an important first step toward reaching such a goal. It was found that the noble-metal co-catalyst was substantially more robust than Ni2P under the application conditions tested, and that only a very small Pt loading was required to achieve H2 production rates comparable to conventional CNx|Pt (0.033 ± 0.0013 % m/m Pt in HGM/CNx|Pt vs 0.91 ± 0.017% m/m Pt in CNx|Pt). Recent work has estimated the costs of slurry catalyst materials TiO2|Pt (1% m/m Pt; $640 USD kg -1 ) and CNx|Ni2P (2% m/m Ni2P; $224 USD kg -1 ), and using the same cost basis, a CNx|Pt composite containing 0.04% m/m Pt would cost $224 USD kg -1 . This brings the cost of a precious metal-containing composite in line with the cost of a Ni2P co-catalyst with higher PR performance and greatly improves the cost compared to a CNx|Pt composite (1% m/m Pt; $800 USD kg -1 ). Furthermore, the areal activity from the floating composites was found to outperform previously reported scalable, reusable panel systems. These findings point toward floating CNx composites as a promising, scalable material for practical solar reforming that addresses the scaling challenges of recyclability and light absorption by the waste solution by using small quantities of noble metals as co-catalysts on a recyclable floating platform.