Hydrogen Evolution from Water Coupled with the Oxidation of As(III) in a Photocatalytic System
journal contribution
posted on 2015-12-30, 00:00 authored by Jian-Ping Zou, Dan-Dan Wu, Shao-Kui Bao, Jinming Luo, Xu-Biao Luo, Si-Liang Lei, Hui-Long Liu, Hong-Mei Du, Sheng-Lian Luo, Chak-Tong Au, Steven L. SuibA series of heterostructured CdS/Sr2(Nb17/18Zn1/18)2O7−δ composites
with excellent photocatalytic ability for simultaneous hydrogen evolution
and As(III) oxidation under simulated sunlight were synthesized and
characterized. Among them, 30% CdS/Sr2(Nb17/18Zn1/18)2O7−δ (30CSNZO)
has the highest in activity, exhibiting a H2 production
rate of 1669.1 μmol·h–1·g–1 that is higher than that of many photocatalysts recently reported
in the literature. At pH 9, As(III) is completely oxidized to As(V)
over 30CSNZO in 30 min of irradiation of simulated sunlight. In the
photocatalytic system, H2 production rate decreases with
the increase of As(III) concentration, and the recycle experiments
show that 30CSNZO exhibits excellent stability, durability, and recyclability
for photocatalytic hydrogen evolution and As(III) oxidation. We propose
a mechanism in which superoxide radical (·O2–) is the active species for As(III) oxidation and the oxidation of
As(III) has an effect on hydrogen evolution. For the first time, it
is demonstrated that simultaneous hydrogen evolution and arsenite
oxidation is possible in a photocatalytic system.
