An efficient water oxidation photoanode based on hematite has been designed and fabricated by tailored assembly of graphene oxide (GO) nanosheets and cobalt polyoxometalate (Co-POM) water oxidation catalysts into a nacre-like multilayer architecture on a hematite photoanode. The deposition of catalytic multilayers provides a high photocatalytic efficiency and photoelectrochemical stability to underlying hematite photoanodes. Compared to the bare counterpart, the catalytic multilayer electrode exhibits a significantly higher photocurrent density and large cathodic shift in onset potential (a369 mV) even at neutral pH conditions due to the improved charge transport and catalytic efficiency from the rational and precise assembly of GO and Co-POM. Unexpectedly, the polymeric base layer deposited prior to the catalytic multilayers improves the performance even more by facilitating the transfer of photogenerated holes for water oxidation through modification of the flat band potential of the underlying photoelectrode. This approach utilizing polymeric base and catalytic multilayers provides an insight into the design of highly efficient photoelectrodes and devices for artificial photosynthesis.
Bibliographical noteFunding Information:
This work was supported by the Basic Science Research Program (2015R1C1A1A02037698 and 2018R1D1A1A02046918) and the Nano-Material Technology Development Program (2017M3A7B4052802) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT of Korea. H.-W.L. acknowledges support from the Basic Research Lab Program (2017R1A4A1015533) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT of Korea.
© 2018 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physics and Astronomy(all)