Photocatalytic Membranes for Solar Fuel Generation

Semiconductor nanoparticles embedded in polymer matrix offer a convenient approach to navigate the electron and hole flow in a photocatalytic membrane. In addition, it also facilitates separation of reduction and oxidation products. We have embedded sevral semiconductor nanoparticles (CdS, AgInS₂ and In₂S₃ ) in a Nafion membrane to induce photocatalytic reactions using visible light. In additon we have also deposited cocatalysts such as Pt, Pd on these membranes to facilitate production of H₂. By inserting the photocatalytic membrane in an H-cell, we can separate the oxidation and reduction products and track the electron flow using steady state photolysis and transient absorption spectroscopy. Using viologen as a probe we have obtained insight into the interfacial electron transfer processes. Directing such vectorial charge transfer in a photocatalytic membrane will be useful in suppressing undesired side reactions (e.g. reoxidation of a reduced product) and facilitating product separation. This approach offers a convenient way for photocatalytic generation of solar fuels.