Strongly Coupled g‐C₃N₄ Nanosheets‐Co₃O₄ Quantum Dots as 2D/0D Heterostructure Composite for Peroxymonosulfate Activation

Abstract

The development of effective approaches for the preparation of 0D quantum dots (QDs)/2D nanosheets (NSs) heterostructures, which have been proven to be favorable for heterogeneous catalysis, is highly desirable but remains a great challenge. Herein, 0D metal oxide nanocrystals-2D ultrathin g-C N nanosheets (Co O /CNNS) heterostructures are synthesized via a facile chemical reaction, followed by annealing in air. Ultrafine Co O QDs (≈2.2-3.2 nm) are uniformly and tightly attached on the surface of g-C N nanosheets. Detailed characterization reveals that the specially designed unique 0D/2D structure is critical to the high photocatalytic performance for the degradation of tetracycline (TC) via peroxymonosulfate (PMS) activation. The optimal catalyst, namely, Co O /CNNS-1100, exhibits excellent performance and ≈98.7% TC can be degraded under visible light irradiation. Moreover, TC degradation is almost completely insusceptible to several real water samples. Meanwhile, other dye pollutants can also be efficiently degraded by the Co O /CNNS-1100/PMS/vis system. The quenching tests display that that the h , ∙OH, O , and SO are responsible for TC removal. The improved photocatalytic performance can be attributed to the synergistic effect of the photocatalytic- and chemical-processes in the PMS activation. This work gives an insight into the development of multifunctional 0D/2D nanocomposites for further potential applications which are not limited to environmental purification.

Designing a 0D/2D S‐Scheme Heterojunction over Polymeric Carbon Nitride for Visible‐Light Photocatalytic Inactivation of Bacteria

“…[5c, 9] High-angle annular dark field transmission electron microscopic (HAADF-TEM) images confirm that these tiny CeO 2 nanocrystallines are homogeneously anchored on the PCN nanosheets ( Figure 2c Figure S3). Thes tatistical particle size distribution of CeO 2 centered at about 5nmr eveals its typical quantum size, [10] which is beneficial for the formation of intimate anchor-hold structure between the CeO 2 and PCN nanosheets. X-ray diffraction (XRD) patterns are recorded to probe the phase structure of the as-prepared samples (Figure 3a).…”

ZIF‐67‐Derived 3D Hollow Mesoporous Crystalline Co3O4 Wrapped by 2D g‐C3N4 Nanosheets for Photocatalytic Removal of Nitric Oxide

“…Diffraction peaks of the (220) and (311) planes of CO are observed in all composites and are gradually enhanced with increasing CO content. The remaining diffraction peaks of CO are difficult to detect in the composites, probably because of the low content and uniform dispersion of CO in CN …”

0D CoP cocatalyst/ 2D g‐C3N4 nanosheets: An efficient photocatalyst for promoting photocatalytic hydrogen evolution

“…As a visible light responsive metal‐free polymer semiconductor, g‐C 3 N 4 , has good thermal/chemical stability, electronic and optical properties, and is widely used in the field of solar energy conversion . The conduction band potential of g‐C 3 N 4 is −1.3 eV (vs, NHE, pH = 7), photogenerated electrons generated under visible light excitation have strong reduction ability . Moreover, the surface group of g‐C 3 N 4 is negatively charged to help build a composite photocatalytic system with other semiconductors.…”

“…[8][9][10] The conduction band potential of g-C 3 N 4 is −1.3 eV (vs, NHE, pH = 7), photogenerated electrons generated under visible light excitation have strong reduction ability. [11][12][13][14] Moreover, the surface group of g-C 3 N 4 is negatively charged to help build a composite photocatalytic system with other semiconductors.…”