Characteristics and Photocatalytics Activities of Ce-Doped ZnO Nanoparticles

Abstract

Ce-doped ZnO nanoparticles with various doping concentrations of cerium ion were prepared by the co-precipitation method. All prepared nanoparticles were characterized by electron spin resonance (ESR), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectroscopy. All nanoparticles show X-ray diffraction pattern that matched with ZnO in its wurzite structure and average grain size was in the range of 13 -16 nm. UV-Vis measurements indicated a red shift of the photophysical response of ZnO after doping that was exhibited in reflection spectra in the visible region between 300 -800 nm. In addition, it has been found from electron spin resonance measurements that defects, which are likely to be oxygen vacancy and an electron trapped at cerium site are formed in our Ce-doped ZnO particles. Photocatalytic activities of Ce-doped ZnO were evaluated by irradiating the nanoparticles solution to ultraviolet light by taking methyl orange as organic dye. The experiment demonstrated that the photodegradation increased as doping concentrations increased at first and then decreased when the doping concentration exceeded 9 at%. It is proposed that the photocatalytic activity is strongly dependent on the formation of oxygen vacancy and an electron trapped at cerium site.

Influence of Co and Dy Doping on the Optical and Magnetic Properties of ZnO Nanoparticles for DMS Application

“…These 4f electrons undergo indirect exchange interactions via 5d or 6s conduction electrons yielding high magnetic moment per atoms due to high orbital momentum. Liu et al found that the room temperature ferromagnetism in gadolinium-doped GaN was due to the interaction of Gd 4f spins via p-d coupling involving holes introduced by the intrinsic defects [20]. Nadia Febiana Djaja and Rosari Saleh found that in Ce-doped ZnO nanoparticles, the photocatalytic activity increased with the increase of cerium ion content and then decreased when the cerium ion exceeded its optimal value [21].…”

Comparison of the photocatalytic degradation of trypan blue by undoped and silver-doped zinc oxide nanoparticles

“…Of these, noble metal ion incorporation have been studying extensively and proved to be very effective in improving the photocatalytic activity and also to tune the optical and electrical properties of ZnO [8]. Various groups have synthesized ZnO:Ce nanoparticles [9], ZnO:Pd nanoparticles [10], ZnO:Al nanoparticles [11], and ZnO:Mn nanoparticles [12] by different method and observed the improved performance compared to pure ZnO nanoparticles. Literature surveys suggested that ZnO or ZnO:Ag is non-toxic in nature and are used in the various biological/medical applications [13].…”

Effect of Ce doping on the structural, optical and magnetic properties of ZnO nanoparticles

“…There are numerous reports on the utilization of several metals for doping such as Nd [19], Sn [20], Ag [21], Mn [22], Ga [23] and Ce [13][14][15][16][17]24]. In this framework, the doping of RE ion in ZnO is of great importance due to signs of tunable luminescence and ferromagnetism at room temperature.…”

“…Ce doped ZnO nanophosphors have been comprehensively studied because of the unusual interaction between the excited states and the host lattice. CeO 2 has a band gap of 3.0 eV and possesses a unique optical characteristic for visible LED and high power laser that are similar to ZnO [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Thus, the Ce doped ZnO nanomaterials also exhibited versatile properties and have been explored to assess the photoluminescence and photoelectrochemical activity under visible light, gas-sensing properties and ferromagnetism [24,29,30].…”

“…Another attractive property of ZnO is photocatalysis. It is because of its non-hazardous nature and tremendous physical and chemical stability [13][14][15][16][17]. Its photocatalytic efficiency depends on the competition between electron-hole recombination process and surface chemical reaction.…”