Compositing effects of CuBi 2 O 4 on visible-light responsive photocatalysts

Beneficial CuO Phase Segregation in the Ternary p-Type Oxide Photocathode CuBi2O4

“…With the limited availability of p-type metal-oxide-based photocathode materials for applications such as CO 2 reduction, significant efforts are dedicated to finding new materials with improved stability, ideal bandgaps, and band energetics at the correct chemical potentials for the desired chemical reactivity. Many such emerging p-type materials are copper-based bimetallics based on the well-known p-type semiconductor cuprous oxide (Cu 2 O). − One such example is CuBi 2 O 4 (CBO), which has a suitable band gap for sunlight harvesting (1.5–1.8 eV) and a relatively positive valence band potential, making it an attractive candidate for CO 2 reduction. − To make meaningful advances toward understanding the fundamental material properties and thereby identify performance-limiting factors, the development of high-quality material of known composition and phase is necessary. Notably with ternary oxides, device properties can vary significantly depending on the ratio of the component elements. − ,, Films are commonly annealed at temperature >500 °C, which can result in sublimation of select elements, , making phase purity and ideal stoichiometry difficult to achieve.…”

Improved Visible Light Photoactivity of CuBi2O4/CuO Heterojunctions for Photodegradation of Methylene Blue and Metronidazole

“…Especially, photocatalyst materials able to degrade or mineralize persistent pollutants such as dyes, pharmaceuticals, pesticides, and other organic compounds which are not naturally degraded in the environment has been intensively investigated. − Nowadays, it is a consensus that the most explored semiconductor material for photocatalytic reactions was TiO 2 ; − however, its photocatalytic activity stands only in the UV region of the solar spectrum (wavelength < 390 nm), limiting severely their practical applications due to the operating costs . As visible light corresponds to almost 45% of the solar radiation, new photocatalyst able to convert solar light to reactive species that may efficiently promote oxidation and/or reduction of pollutant molecules has been the object of research in the last years. − …”

Novel CoFe2O4/CuBi2O4 heterojunction p–n semiconductor as visible‐light‐driven nanophotocatalyst for C (OH)–H bond activation

“…The XPS spectrum for O 1s displays three main peaks at 529.9, 530.9, and 532.0 eV corresponding to the metal-O, the chemisorbed oxygen, and the metal-OH groups on the surface, respectively (Figure [41][42][43][44] The Bi 4f XPS signals demonstrate two sharp peaks centered at 159.1 and 164.4 eV, which are allocated to the binding energies of Bi 4f 7/2 and Bi 4f 5/2 , respectively, illustrating the presence of Bi 3+ (Figure 9c). [28,[45][46][47] As exhibited in Figure 9d, the XPS spectra of Cu demonstrate two peaks at 933.8 and 953.6 eV, which are related to Cu 2p 3/2 and Cu 2p 1/2 , respectively. Two peaks at 931.8 and 948.5 eV are attributed to Cu + in Cu 2 O species.…”