Hierarchical ZnO Decorated with CeO₂ Nanoparticles as the Direct Z-Scheme Heterojunction for Enhanced Photocatalytic Activity

Abstract

Development of a high-efficiency heterojunction with an improved photocatalytic property is regarded as a promising way to decontaminate wastewater. Herein, the direct novel Z-scheme heterojunction formed between CeO 2 nanoparticles and hierarchical ZnO was synthesized through the wet chemistry method and then the heat-treatment technique. The as-synthesized ZnO/CeO 2 composites display highly enhanced photocatalytic rhodamine B (RhB) degradation compared with pristine ZnO and CeO 2 . Specifically, ZnO/CeO 2 -3 (mass fraction of CeO 2 , 30%) shows good photostability and the best removal efficiency for photodegradated RhB, which are almost 2.5 and 1.7 times than pristine ZnO and CeO 2 , respectively. On the basis of the detailed characterizations and the degradation behavior of as-prepared samples over RhB, the formed heterojunction between the hierarchical ZnO and CeO 2 nanoparticles is confirmed as the direct Z-scheme heterojunction. The heterojunction system shows fast transfer, high-efficiency separation, and long lifetime of photoinduced charge carriers, as well as enhanced redox capacity. This study affords a novel approach to construct ZnO-based Z-scheme heterojunctions for the photocatalytic applications.

Cerium-Oxide-Nanoparticle-Decorated Zinc Oxide with Enhanced Photocatalytic Degradation of Methyl Orange

“…Introducing Nd into ZnO can induce defect formation (like antisite oxygen and interstitial oxygen) in Nd-doped ZnO powder, which would play an important role in trapping electron carriers and charge separation [33]. Presently, there are few research reports on Ce-doped ZnO nanocomposites for photocatalytic applications [34,35]. Shen et al prepared the 3D flower-like mesoporous cerium-zinc oxide for sunlight-driven photodegradation of Rhodamine B (RhB), which showed 85.1% degradation in 125 min [36].…”

An Efficient Photocatalyst Based on Black TiO2 Nanoparticles and Porous Carbon with High Surface Area: Degradation of Antibiotics and Organic Pollutants in Water

“…The CB values of BTN, 5 % BTN@PC, 10 % BTN@PC and 15 % BTN@PC are ca. −0.81 eV, −0.85 eV, −0.83 eV and −0.80 eV, respectively, and the calculated energy band gaps can be seen in Figure b …”

“…À 0.81 eV, À 0.85 eV, À 0.83 eV and À 0.80 eV, respectively, and the calculated energy band gaps can be seen in Figure 7b. [45][46][47] In summary, a possible photocatalytic mechanism is illustrated in Scheme 2. Under visible-light irradiation, the photogenerated electrons are excited from the VB to the CB of BTN.…”

A Novel CuBi2O4/BiOBr Direct Z‐scheme Photocatalyst For Efficient Antibiotics Removal: Synergy of Adsorption and Photocatalysis on Degradation Kinetics and Mechanism Insight

“…Combined with the band gap energy of CuBi 2 O 4 in Figure 10b, the conduction band edge potential of CuBi 2 O 4 was calculated to be À 0.59 V by the equation of E CB = E VB -E g . [62] Similarly, the E VB and E CB of BiOBr were estimated to be + 2.97 V and + 0.38 V, respectively (Figure 11b). Meanwhile, as an n-type semiconductor (Figure S30), the conduction band energy of BiOBr also could be verified by the Mott-Schottky analysis.…”