The generation of hydrogen from water using light could be a method of providing a clean fuel, which is clearly important for our growing energy needs. We are using perylene bisimides (PBIs) as photocatalyss for hydrogen evolution from water. For this process, we need to add a nanoparticle co-catalyst. We need to know whether the nanoparticles affects the assembly of the PBIs at high and low pH in order to design and optimise our systems. Currently, we have to assume that the particles have no effect on the assembly; if this is not true, we need to re-interpret our data.