Nanocellulose-derived carbon/g-C3N4 heterojunction with a hybrid electron transfer pathway for highly photocatalytic hydrogen peroxide production

Using oxygen reduction for the photocatalytic production of hydrogen peroxide (H2O2) has been considered a green and sustainable route. In the present study, to achieve high efficiency, graphitic carbon nitride (g-C3N4) 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-C3N4 alone. The well-defined carbon/g-C3N4 heterojunction-type material exhibits as high as 1.10 mmol L-1h−1 of photo-production of H2O2 under visible light, which is 4.2 times higher than that yielded by pristine g-C3N4 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.