Photoelectrocatalytic processes (PECs) integrate the principles of photocatalysis (PC) and electrocatalysis to improve the generation and stability of charge carriers, making them an effective way to produce H2 and H2O2. Reactor design is critical for optimal energy efficiency in activating advanced photocatalysts. Low energy efficiency in current PEC flat-plate reactor designs is due to light attenuation by glass materials and water, and limited surface area for photo-excitation. To overcome these challenges, we propose a new architecture called the optoelectrode that utilizes visible wavelength (>400 nm) light emitting diodes (LEDs) to launch light into one end of durable polymer optical fibers (POFs). The POFs side-emit light to activate non-platinum group element-based nanomaterials (NMs) embedded in porous polymers on the POF surface. Our reactor can house single or bundles of >100 POF optoelectrodes (~1.5 mm diameter & 10 to >50 cm lengths) and we propose two architectures for producing resources from water. In previous work, we have demonstrated that: A cathodic optoelectrode produces H2 from water using two NMs embedded within porous layer of the POF surface, creating a PEC-POF system that generates H2 on the fiber surface. A photocatalytic optoelectrode with a single NM (iron-based metal organic framework (MOF)) embedded within porous layer of the POF surface, produces >1 wt% H2O2 from water. Compared to flat glass-plate architectures with the same NM, POF optoelectrodes achieve >700% larger catalyst surface area and >300% better incident photon-to-current efficiency (IPCE) with lower energy input. POF is also agnostic to nanomaterial type, enabling deposition of tunable nanomaterials for specific wavelengths using LED or polychromatic light. Bundling large numbers (n>100) of POF optoelectrodes enables higher packing geometries (i.e., m2 catalyst surface per m3 reactor volume) than flat-electrode PEC reactors, minimizing reactor size and power requirements. Anticipated
Benefits: Sustainably produced hydrogen can reduce dependence on terrestrial supplies of hydrogen -containing resources. Photoelectrocatalytic polymeric optical fibers (POF) use significantly less energy with a lighter weight footprint than conventional electrolysis technologies. Sustainably produced liquid hydrogen peroxide can be used for surface disinfection applications. Photocatalytic polymeric optical fibers produce hydrogen peroxide from only water and light, without reliance upon dissolved chemical reagents. Sustainable hydrogen and hydrogen peroxide production
