Photoelectrochemically driven nanoparticulate semiconductors as nanobipolar electrodes for advanced water remediation

Abstract

Photochemistry is of broad interest for applications in catalysis, synthesis, and environmental remediation. However, photochemistry applications are largely hampered by rapid recombination of photogenerated charges and/or limited surface areas of photoelectrodes. Combining the advantages of photochemistry and electrochemistry, here we report a strategy using photoelectrochemically driven semiconducting nanoparticles to function as nanobipolar electrodes. The system shows enhanced production of photogenerated charges and has an extended heterogeneous:homogeneous photoelectrode interface and can be applied as an advanced oxidation process for water remediation. Complete removal of refractory pollutants was achieved with a series of n- and p-type semiconductors over a wide range of pH values with tolerance for anions and resistance to photocorrosion. This strategy achieves higher reaction rates than photocatalysis and conventional photoelectrocatalysis (61 and 24 times, respectively) and, hence, lower energy consumption. This bipolar photochemistry strategy may have a wide range of potential applications in energy-, synthesis-, and environment-related fields. • Bipolar behavior of photoelectrochemically driven semiconductors is reported • Nanoparticulate semiconductors act as nanobipolar electrodes • The developed strategy helps direct charge transfer in photochemical reactions • Application as an advanced oxidation process for water remediation is demonstrated Lei et al. develop a photoelectrochemical system with nanoparticulate semiconductors that function like nanobipolar electrodes for water remediation. The developed strategy is tested with a series of n-type and p-type semiconducting nanoparticles for degradation of refractory pollutants.