Enhanced visible light photodegradation activity of RhB/MB from aqueous solution using nanosized novel Fe-Cd co-modified ZnO

Abstract

A series of novel Fe-Cd co-doped ZnO nanoparticle based photocatalysts are successfully synthesized by sol-gel route and characterized using scanning electron microscopy (SEM), energy dispersive X-ray emission (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) techniques. The photocatalytic activity of ZnO nanoparticles doped with various atomic weight fraction of Fe and Cd has been investigated under visible light irradiation using the Methylene Blue and Rhodamine B dye in aqueous solution. The FeCd (2%):ZnO (ZFC-1) exhibit the highest photocatalytic activity in terms of rate constant as KMB = 0.01153 min−1 and KRhB = 0.00916 min−1). Further, the re-usability of the ZFC-1 photocatalyst is studied which confirms that it can be reused up to five times with nearly negligible loss of the photocatalytic efficiency. Moreover, the role of photoactive species investigated using a radical scavenger technique. The present investigations show that the doping concentration plays significant role in photocatalytic performance. The visible light absorption shown by Fe-Cd co-doped ZnO nanoparticles is much higher than that of undoped body probably due to co-doping, and the charge carrier recombination is decreased effectively which yields a higher photocatalytic performance. The mechanism for the enhancement of photocatalytic activity under visible light irradiation is also proposed.

Assessment of synthesis approaches for tuning the photocatalytic property of ZnO nanoparticles

“…: (ii), has been deconvoluted into two peaks (Gaussian fitting) at 529.9 eV and 531.5 eV, respectively. The peak at the lower binding energy (529.9 eV) is accredited to the anionic (2−) states of oxygen in the wurtzite geometry of Zn 2+ ion array [58], while the peak at the higher binding energy (531.5 eV) corresponds to bulk oxygen (O 1s) involvement from the adsorbed oxygen of the polymer used (PEG) [59,60]. Similarly, fig.…”

New Electrospun ZnO:MoO3 Nanostructures: Preparation, Characterization and Photocatalytic Performance

“…The conduction band (CB) and valence band (VB) potentials of ZnO:MoO 3 were calculated using the following equations [ 21 ]. E VB = χ − E e + 0.5E g E CB = E VB − E g where χ and E e , are the electronegativity (for ZnO, the value is approximately 5.79 eV) [ 22 ] and the free electron energy on the hydrogen scale (approximately 4.5 eV), respectively. The calculated values of E VB and E CB are listed in Table 2 .…”

High-throughput Production of ZnO-MoS2-Graphene Heterostructures for Highly Efficient Photocatalytic Hydrogen Evolution

“…In recent decades, various methods and nanostructures have been developed to realize efficient hydrogen generation [1,2]. As examples, a photostable photocatalyst of n-doped zinc oxide (ZnO)/graphene oxide has been developed for improving the mineralization and photodegradation of organic dye under visible light [3,4,5]; ‘‘green” SnS 2 quantum dots/reduced graphene oxide composites have been fabricated with enhanced photocatalytic performance [6]; and Pd-decorated ZnO−graphene oxide nanocomposites have been reported with significantly enhanced photocatalytic activities based on a charge separation mechanism [7]. However, due to the limited lifetime of excited electrons and holes, as well as the poor abilities of visible-light absorption in ordinary materials, high-efficient mass-produced sunlight-driven photocatalysts remain strongly desired.…”