The Effect of the Reducing Sugars in the Synthesis of Visible-Light-Active Copper(I) Oxide Photocatalyst

Abstract

In the present work, shape tailored Cu2O microparticles were synthesized by changing the nature of the reducing agent and studied subsequently. d-(+)-glucose, d-(+)-fructose, d-(+)xylose, d-(+)-galactose, and d-(+)-arabinose were chosen as reducing agents due to their different reducing abilities. The morpho-structural characteristics were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS), while their photocatalytic activity was evaluated by methyl orange degradation under visible light (120 min). The results show that the number of carbon atoms in the sugars affect the morphology and particle size (from 250 nm to 1.2 µm), and differences in their degree of crystallinity and photocatalytic activity were also found. The highest activity was observed when glucose was used as the reducing agent.

Photoinhibitive Properties of α-MoO3 on Its Composites with TiO2, ZnO, BiOI, AgBr, and Cu2O

“…The as-prepared semiconductors and their composites were analyzed via XRD and SEM measurements to ascertain the reproducibility of photocatalysts and the presence of MoO 3 in the composites. The structure of the as-prepared pristine photocatalysts was reproducible: TiO 2 was obtained in the form of anatase [ 18 ], BiOI in tetragonal matlockite [ 19 ], ZnO in hexagonal wurtzite [ 5 ], AgBr [ 4 ], and Cu 2 O in cubic form [ 6 ] ( Figure 1 ). The as-prepared MoO 3 presented an orthorhombic phase with (021) a dominant crystallographic plane ( Figure 1 b).…”

“…A total of 1 g of Ammonium heptamolybdate tetrahydrate (AHM) (99.5%, NH 4 ) 6 Mo 7 O 24 4H 2 O, Molar Chemicals, Halásztelek, Hungary) was dissolved in 90 mL of 1 M HNO 3 (65%, Molar Chemicals, Halásztelek, Hungary), and stirred for 15 min. The transparent solution was poured into a Teflon ® -lined stainless-steel autoclave (Toption Instrument CO., LTD., Xi’an, China) and heated up to 180 °C for 20 h. After hydrothermal crystallization, the obtained precipitate was washed with distilled water several times and dried at 40 °C for 24 h. All photocatalysts were synthesized in accordance with our previous works (TiO 2 [ 18 ], ZnO [ 5 ], BiOI [ 19 ], AgBr [ 4 ], and Cu 2 O [ 6 ]).…”

“…Due to excitation, charge separation occurs, resulting in active radicals in an aqueous medium, such as ·OH, ·O 2 − . Numerous semiconductors (TiO 2 [ 1 ], WO 3 [ 2 ], BiOI [ 3 ], AgBr [ 4 ], ZnO [ 5 ], Cu 2 O [ 6 ]) with various structural properties were recognized as individual photocatalysts (depending on the irradiation type: UV, visible, or NIR light) [ 7 ]. However, further efficiency improvement can be achieved by making heterostructures where the lifetime of the photogenerated charge carriers is extended.…”