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

Abstract

Nanosized CoFe2O4/CuBi2O4 heterostructure was obtained by solvent‐free thermal processing and was characterized using a series of structural, physicochemical, and analytical techniques. The CuBi2O4 and CoFe2O4 nanoparticles demonstrated poor photoactivity due to their fast charge recombination and negligible visible light absorptivity, respectively. In contrast, the prepared heterojunction CoFe2O4/CuBi2O4 nanocomposite consisting of an array of nanocolumns approximately 20 nm in width displayed nearly twofold higher photocatalytic activity than CoFe2O4 or CuBi2O4 nanostructures alone toward the C (OH)–H bond activation. This nanocomposite exhibits photocatalytic efficiency as high as 98% with very high stability. The increased photocatalytic reactivity could be related to the effective Z‐scheme mechanism of photogenerated charge carrier separation between CoFe2O4 and CuBi2O4 in the nanocomposite, which reduces the electron–hole recombination. The results of this work provide a promising approach to the design and preparation of heterostructured photocatalysts for oxidation reactions.

Photocatalytic conversion of MB dye using Co3O4 QDs‐Ag2MoO4 as an active heterojunction photocatalyst under visible light irradiation

“…The Co 3 O 4 QDs‐AMO nanocomposites illustrate the strong absorbance in the visible and UV regions in comparison with pure AMO particles. This feature could modify the photoactivity of Co 3 O 4 QDs‐AMO because of the more efficient usage of solar energy 39–41 . Hence, the bandgap energies ( E g ) of AMO and Co 3 O 4 QDs‐AMO were approximated using the Tauc plots on the base of the Kubelka–Munk function, by (αhν) 2 plot versus hν 30,42 .…”

Visible light‐driven Z‐scheme NiO/BiO2−x heterojunction for efficient degradation of organic pollutants in water

“…According to the Z path (Figure 10), the CB e ÁOH and degraded organic pollutants to small toxic molecules in wastewater. [1,49,50] Therefore, for this system, the Z scheme mechanism may be more reasonable. In summary, the construction of Z-scheme NiO/BiO 2Àx heterojunction can improve the degradation efficiency of organic pollutants.…”

“…Therefore, effective measures must be taken to reduce the content of organic pollutants. [1,2] Compared with traditional methods, semiconductor photocatalysis technology has mild reaction conditions and high solar energy utilization, which is a green technology with important application prospects in the field of wastewater treatment. [3][4][5][6] However, single semiconductor has faster electron-hole pair recombination efficiency and poorer degradation rate of organic pollutants.…”

Enhanced photocatalytic conversion of organic dyes using CeCoO3/MoS2 heterojunction as a highly effective visible‐light‐driven photocatalyst

“…[6] The photocatalytic efficiency of ZnO and TiO 2 has some weaknesses, such as rapid charge recombination, activation under UV light, and lack of active sites. [7,8] Over the last few years, inorganic perovskite oxides (ABO 3 ), which A and B are rare earth and transition metal on the first row, respectively, have attracted considerable research interest owing to their special chemical and physical properties, [9] extraordinary electrical and optical properties, high performance, ease of fabrication, and low cost. [10] The high-efficiency results from the magnificent characteristics of perovskites including high absorbance, [11,12] charge carrier transport, [13,14] long exciton lifetimes, [15,16] and adjustable bandgap.…”

“…[ 6 ] The photocatalytic efficiency of ZnO and TiO 2 has some weaknesses, such as rapid charge recombination, activation under UV light, and lack of active sites. [ 7,8 ]…”