Z-scheme photocatalytic production of hydrogen peroxide over Bi4O5Br2/g-C3N4 heterostructure under visible light

摘要

Photocatalytic production of hydrogen peroxide from water and oxygen is a promising technique due to the green and sustainable solar-to-chemical energy conversion. However, in the absence of organic sacrificial agents as electron donors, the relatively low photocatalytic H2O2 productivity is still far from satisfactory. Herein, we present a Z-scheme photocatalytic production of hydrogen peroxide over Bi4O5Br2/g-C3N4 heterostructure under visible light without additive organics. The obtained Bi4O5Br2/g-C3N4 heterostructure exhibited a highest H2O2 production of 124 mu M in 60 min by a Z-scheme photocatalytic mechanism. The photoinduced electrons of Bi4O5Br2 combine with the holes of g-C3N4 at the contact interface, and the e(-) and h(+) of the heterostructure are mainly derived from the conduction band of g-C3N4 and valence band of Bi4O5Br2, respectively. As such, more e(-) and h(+) of Bi4O5Br2/g-C3N4 heterostructure are available to reduce oxygen and oxidize water, respectively, with more O-center dot(2)- and (OH)-O-center dot generated and thus more H2O2 produced.