The visible light catalytic properties of carbon quantum dots/ZnO nanoflowers composites

Abstract

Carbon quantum dots (C QDs)/ZnO nanoflowers composites were prepared via a simple technical route through which ZnO nanoflowers were prepared by electrospinning-hydrothermal synthesis and dispersed in C QDs solution, then dried at 80°C. The results indicated that ZnO nanoflowers were well combined with C QDs. The visible light photocatalytic activity of C QDs/ZnO nanoflowers coposite was investigated by degradation of Rhodamine B under visible light irradiation, and it is demonstrated that the photocatalytic performance of this composites was significantly enhanced compared with that of pure ZnO nanoflowers. Furthermore, the unique upconverted photoluminescence behaviour of the carbon dots and the novel 3-D structure of the ZnO were considered as the main reasons of this enhancement.

Multi-shelled ZnO decorated with nitrogen and phosphorus co-doped carbon quantum dots: synthesis and enhanced photodegradation activity of methylene blue in aqueous solutions

“…Among all the composites of CQD-decorated multi-shelled ZnO, the obtained ZnO composites exhibit highest photocatalytic activity when the amount of the CQD solution is controlled at 2 g. The reason for this may be that the CQD/ZnO composite can improve the light utilization through its unique up-conversion characteristics; 35 however, the photocatalytic activity of the carbon quantum dots is weaker than that of ZnO. Thus, the higher the content of the carbon quantum dots decorated on the ZnO shells, the more the competition between the light absorption capacities of ZnO and carbon quantum dots; this will lead to a decline in the photocatalytic activity; 36 to study the photocatalytic activity of ZnO decorated with different kinds of carbon quantum dots, we have selected the same decoration ratio (the amount of CQDs in all the adsorption CQD solutions is controlled at 2 g) as a standard to formulate the C T / C 0 -time and ln(C 0 /C T )-time graphs, as shown in Fig. 7.…”

“…7b exhibits the linear tting line of the curve of ln(C 0 / C T ) versus time, where the slope represents the photocatalytic reaction rate constant. 36 Table 1 lists the reaction kinetics equation and the corresponding parameters of the photocatalytic degradation of MB for the as-prepared photocatalysts. The apparent reaction rate constants (k) are 0.0353, 0.0424, 0.0417, 0.0439, and 0.0725 min À1 for pure ZnO, 2 g-CQD/ZnO, 2 g-NCQD/ZnO, 2 g-PCQD/ZnO, and 2 g-NPCQD/ZnO, respectively.…”

“…35 In this regard, the CQDs could play an important role in the design of composite semiconductor photocatalysts. Zhang et al 36 synthesized CQD/ZnO nanoower composites by a two-step method and found that the prepared composite exhibited excellent visible-light catalytic activity towards the degradation of rhodamine B. Ding et al 37 synthesized carbon quantum dots (CQDs) attached on the surface of ZnO with irregular, hierarchical pores. The CQD/ ZnO composites reported in the literature have been synthesized by a facile process in which the ZnO foam is dispersed in a CQD solution.…”

Distribution of different surface modified carbon dots in pumpkin seedlings

“… 13 – 15 . There are some fascinating properties such as chemical inertness, lack of blinking, low toxicity 16 – 18 , and excellent biocompatibility relative to traditional organic dyes and inorganic semiconductor quantum dots 19 – 22 .…”

Morphology controlled synthesis of Sm doped ZnO nanostructures for photodegradation studies of Acid Blue 113 under UV-A light

“…Recently, enhanced photocatalytic degradation against various organic dyes under different light irradiations using different ions doped ZnO and TiO 2 nano/microstructures has been reported [12][13][14][15][16]. Zhang et al [17] have reported the visible light catalytic properties of carbon quantum dots/ZnO nanoflowers composites, and found that the enhanced photocatalytic properties with respect to the carbon quantum dots and also Khataee et al [18] have reported the sonocatalytic degradation of a textile dye over Gd-doped ZnO nanoparticles and their results revealed that the Gd-doped ZnO nanoparticles can be used as a promising catalyst for degradation of organic pollutants with great reusability potential. There are very few attempts have been made for the degradation of organic dyes using Sm 3?…”