scholarly journals Phase Transformation, Photocatalytic and Photoluminescent Properties of BiPO4 Catalysts Prepared by Solid-State Reaction: Degradation of Rhodamine B

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1007
Author(s):  
Abdessalam Bouddouch ◽  
Elhassan Amaterz ◽  
Bahcine Bakiz ◽  
Aziz Taoufyq ◽  
Frédéric Guinneton ◽  
...  

Polycrystalline bismuth phosphate BiPO4 was synthesized by solid-state reaction at different temperatures varying from 500 to 900 °C. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS) and Raman spectroscopy. The low-temperature phase of BiPO4 has monoclinic structure with a space group P21/n, and was transformed into the monoclinic phase P21/m with a slight distortion of monoclinic lattice when it was heated above 500 °C. The effect of the transformation on the structure, morphology and photocatalytic properties was examined. The photocatalytic activity of each sample, in presence of Rhodamine B (RhB) in aqueous solution, was carried out and analyzed under UV light irradiation. Photoexperiments showed that the material prepared at 500 °C is the best catalyst with degradation efficiency of the order of 96% after 12 min of reaction time under UV light irradiation. This high photocatalytic efficiency could be due to their structural and morphological changes. The photocatalytic degradation mechanism of RhB in the presence of the best photocatalyst BiP-500 °C is proposed. The stability of the catalyst was also examined by carrying out four successive tests of the degradation in the presence of BiP-500 °C. Total organic carbon (TOC) was used to further estimate the rate of mineralization in the presence of BiP-500 °C (83% TOC removal). Photoluminescence experiments performed under UV-laser light irradiation revealed emissions in the green-orange range, with optimal intensities for the mix systems observed at 550 °C.

2007 ◽  
Vol 534-536 ◽  
pp. 1069-1072 ◽  
Author(s):  
Atsushi Fujita ◽  
Hiroaki Matsushita ◽  
Akinori Katsui

Lanthanide tantalite LnTaO4 (Ln= La, Nd, Sm, Dy, Er and Tm) was synthesized by a solid state reaction between mixed powders of Ln2O3 (Ln=La, Nd, Sm, Dy, Er and Tm) and Ta2O5. The single-phase LnTaO4 was prepared by sintering at temperatures of 1423-1673 K in air. The SEM observation showed that the particles were provided with the growth steps and the depeloped facets. The photocatalytic activity for water splitting of LnTaO4 prepared was measured under UV light irradiation. The activity obtained was higher than that previously reported. These results suggested the crystallinity of LnTaO4 photocatalysts correlates closely with the efficiency of water splitting.


2018 ◽  
Vol 13 ◽  
pp. 117739011876336 ◽  
Author(s):  
Eman Alzahrani

Fast Green (FCF) dye is commonly used in both cytology and histology applications. Previous studies have found that it can cause mutagenic and tumorigenic effects in experimental human and animal populations. It can also be a source of skin, eye, respiratory, and digestive irritation. The purpose of this study was to examine the use of thin film membranes to degrade FCF. A thin film membrane of chitosan (CS) was fabricated and subsequently filled with zinc oxide nanoparticles (ZnO) or ZnO/CuO-heterostructured nanocomposites. The CS membrane was used as a matrix, and the nanomaterials were used as photocatalysts. The prepared membranes were characterised by four analytical techniques: atomic force microscopy, scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray analyses. The photocatalytic activity of the fabricated membranes was evaluated by performing experiments in which aqueous solutions of FCF dye that contained the fabricated membrane were irradiated with solar light or UV light. The photodegradation percentage was spectrophotometrically determined by monitoring the maximum wavelengths (λmax) of FCF at 623 nm for different irradiation times. The decolourisation percentages of the dye under solar light were 57.90% and 60.23% using the CS-ZnO and CS-ZnO/CuO membranes, respectively. When UV light irradiation was employed as the source of irradiation, the photodegradation percentages of FCF were 71.45% and 91.21% using the CS-ZnO and CS-ZnO/CuO membranes, respectively. These results indicated that the best photocatalytic system for the degradation of FCF dye was CS-ZnO/CuO membrane in combination with UV light irradiation. The study also found that it was easy to separate the prepared membranes after the reaction without the need for a centrifuge or magnet. The results demonstrate the potential for CS-ZnO and CS-ZnO/CuO membranes for use as effective sorbents during the process of photodegradation of harmful dyes within waste water recycling practices.


2016 ◽  
Vol 16 (4) ◽  
pp. 3684-3689 ◽  
Author(s):  
Xin Min ◽  
Zhaohui Huang ◽  
Minghao Fang ◽  
Yan’gai Liu ◽  
Chao Tang ◽  
...  

In this paper, M3(VO4)2 (M = Mg, Ca, Sr, and Ba) self-activated phosphors were prepared by a solid-state reaction method at 1,000 °C for 5 h. The phase formation and micrographs were analyzed by X-ray diffraction and scanning electron microscopy. The Ca3(VO4)2 phosphor does not show any emission peaks under excitation with ultraviolet (UV) light. However, the M3(VO4)2 (M = Mg, Sr, and Ba) samples are effectively excited by UV light chips ranging from 200 nm to 400 nm and exhibit broad emission bands due to the charge transfer from the oxygen 2p orbital to the vacant 3d orbital of the vanadium in the VO4. The color of these phosphors changes from yellow to light blue via blue-green with increasing ionic radius from Mg to Sr to Ba. The luminescence lifetimes and quantum yield decrease with the increasing unit cell volume and V–V distance, in the order of Mg3(VO4)2 to Sr3(VO4)2 to Ba3(VO4)2. The emission intensity decreases with the increase of temperatures, but presents no color shift. This confirms that these self-activated M3(VO4)2 phosphors can be suggested as candidates of the single-phase phosphors for light using UV light emitting diodes (LEDs).


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mingjie Ma ◽  
Weijie Guo ◽  
Zhengpeng Yang ◽  
Shanxiu Huang ◽  
Guanyu Wang

TiO2/fine char (FC) photocatalyst was prepared via sol-gel method with tetrabutyl titanate as the precursor and FC as the carrier. The structural property of TiO2/FC photocatalyst was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the photocatalytic activity of TiO2/FC was evaluated by photocatalytic degradation of rhodamine B (RhB) aqueous solution under UV light irradiation. The results showed that TiO2was successfully coated on the surface of FC, and the TiO2/FC photocatalyst had better photocatalytic efficiency and stability for degradation of RhB under UV light illumination as compared to that of the pure TiO2and FC. The study provided a novel way for the application of FC to the photocatalytic degradation of organic wastes.


2014 ◽  
Vol 289 ◽  
pp. 224-229 ◽  
Author(s):  
Qizhao Wang ◽  
Juan Hui ◽  
Li Yang ◽  
Haohao Huang ◽  
Yuxia Cai ◽  
...  

Evergreen ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 280-284
Author(s):  
Nur Izzah Iwanina Zamri ◽  
Siti Lailatul Noramalina Zulmajdi ◽  
Eny Kusrini ◽  
Karina Ayuningtyas ◽  
Hartini M. Yasin ◽  
...  

1993 ◽  
Vol 137-139 ◽  
pp. 153-164
Author(s):  
Akira Enokihara ◽  
Shigemi Kohiki ◽  
Kentaro Setsune ◽  
Kiyotaka Wasa

2017 ◽  
Vol 8 ◽  
pp. 604-613 ◽  
Author(s):  
Subia Ambreen ◽  
Mohammad Danish ◽  
Narendra D Pandey ◽  
Ashutosh Pandey

Ta2O5 nanoparticles have been synthesized from alkoxy carboxylates of tantalum via the sol–gel route. Tantalum alkoxides were reacted with chlorocarboxylic acids in order to lower the susceptibility hydrolysis. When these modified alkoxy carboxylates were used in the sol–gel synthesis, they yielded Ta2O5 nanoparticles of better properties than those of the alkoxide-derived Ta2O5 nanoparticles. These nanoparticles efficiently removed rhodamine B under UV light irradiation.


Sign in / Sign up

Export Citation Format

Share Document