Nanocellulose-derived carbon/g-CN heterojunction with a hybrid electron transfer pathway for highly photocatalytic hydrogen peroxide production.

Using oxygen reduction for the photocatalytic production of hydrogen peroxide (HO) has been considered a green and sustainable route. In the present study, to achieve high efficiency, graphitic carbon nitride (g-CN) was obtained using thermal polymerization from a bi-component precursor and was then assembled with cellulose nanofibers. It was found that a small quantity of cellulose nanofibers that generates carbon fibers upon pyrolysis greatly improves the photocatalytic activity compared with that of g-CN alone. The well-defined carbon/g-CN heterojunction-type material exhibits as high as 1.10 mmol Lh of photo-production of HO under visible light, which is 4.2 times higher than that yielded by pristine g-CN from a single precursor. A comprehensive characterization of the photocatalyst enables us to delineate the effect of the carbon nanofiber with respect to porosity, electron-hole separation, band gap regulation, and especially the electron transfer pathway. Our results demonstrate that nanocellulose-derived carbon, when precisely assembled with other functional material such as a photocatalyst, is a promising promoter of their activity.