Construction of a P, N Co-Doped Nanocarbon-Embedded g-C3N4 Hollow Sphere Nanoreactor for the Efficient Photocatalytic Production of Hydrogen Peroxide

The photocatalytic production of hydrogen peroxide (H2O2) by graphitic carbon nitride (g-C3N4) has been a promising technique. However, its photocatalytic property is limited by the easy combination of photogenerated charges, low reaction selectivity, and reaction rate in the O-2 reduction reaction (ORR) process. Hence, a photocatalytic nanoreactor system is designed and constructed by embedding the P, N co-doped carbon nanomaterials in a g-C3N4 hollow sphere. The P, N co-doped nanocarbon as an acceptor and transporter for photo-generated electrons can inhibit the combination of photogenerated carriers with electron transfer from CNHS to P, N-C. Particularly, the P, N co-doped carbon active sites are beneficial to improve two-electron (2 e(-)) ORR selectivity with favorable formation of hydroperoxo species (-OOH). With the promoted electron transfer and 2 e(-) ORR selectivity for H2O2 production in the confinement domain of the hollow sphere interior, the resultant photocatalytic system exhibits a high production rate towards H2O2 of 239.5 mu mol h(-1) g(-1) in pure water and 4568 mu mol h(-1) g(-1) with isopropanol hole scavenger, which is 14.1 and 35.7 times those of bulk g-C3N4. This study offers an efficient avenue for the construction and improvement of photocatalysts and an insight into the understanding of photocatalytic H2O2 production.

Automated summary

By embedding P, N co-doped carbon nanomaterials in a hollow sphere of g-C3N4, a photocatalytic nanoreactor system was designed and constructed. This system exhibits high production rate for H2O2 by promoting electron transfer and improving reaction selectivity. This study offers a new avenue for the construction and improvement of photocatalysts.