Manipulating Luminescence and Photocatalytic Activities of BiVO₄ by Eu³⁺ Ions Incorporation

Abstract

BiVO4 was selected as a model to manipulate the luminescence and photocatalysis by Eu3+ ions incorporation. Eu3+-uniformly doped and surface-localized BiVO4 was prepared by a coprecipitation route and cation exchanges, respectively. The phase-formations, surface characteristics, and band structures were measured. A comparative study of photoenergy conversion activities, that is, photocatalysis and photoluminescence, was conducted. Eu3+-surface-localizing on BiVO4 improves both visible light harvest and photodegradation on RhB dye, while, Eu3+-uniformly doping deteriorates the photocatalysis of BiVO4. In Eu3+-uniformly doped BiVO4 nanoparticles, 5D0 → 7F0,1,2,3,4 luminescence quenched in the monoclinic phase, whereas it could be observed in the tetragonal formation. Differently, Eu3+-surface-localized BiVO4 with the monoclinic formation showed both enhanced Eu3+ luminescence and improved photocatalysis. A band model was proposed to discuss the luminescence mechanism. Bi 6s levels could contribute different energy positions in band structures of monoclinic and tetragonal phases, which play a vital role in the photoenergy conversion. Eu3+ ions incorporated in BiVO4 could be used to study multimodal photoenergy models such as photocatalysis and photoluminescence.

Review on the preparation and performance improvement methods of bismuth photocatalyst materials

“…Rare earth ion doping can effectively optimize photocatalytic performance by narrowing the band gap, expanding absorption, changing the band position, and promoting carrier separation, while rare earth elements with incomplete occupation of 4F orbital can increase light absorption and separate photogenerated charges. 108 Gu et al 109 used hydrothermal method to replace Bi 3+ with Ce 3+ to prepare BiVO 4 doped with Ce, in which doping of Ce induced the transformation of bismuth vanadate from monoclinic phase to tetragonal phase structure. Bi 3+ ions of Ce 4+ in the substituted lattice produce charged defect states.…”

New application of resin macrospheres: preparation of Bi2O3/C photocatalysts from an inexpensive organic carbon source and their application in dye wastewater treatment

“…30 Photoluminescence spectroscopy (PL) was performed using a Hitachi F-4500 fluorescence spectrophotometer, and with the aid of it, the electron hole movement of the samples was measured. 31 The photocurrent ( i – t ) curve and electrochemical impedance spectra (EIS) were obtained using a CHI660E electrochemical workstation from Shanghai Chenhua Instrument Co., Ltd.…”

Structure, morphology and photocatalytic performance of europium-doped bismuth vanadate

“…In particular, lanthanide ions with a unique 4f electron configuration are considered to be efficient dopants to enhance the photocatalytic activity of BiVO 4 . 4 To date, several studies have focused on lanthanide ion-modified monoclinic phase BiVO 4 photocatalysts, such as Ce, La, Gd, Nd and Sm. 5 These findings established the enhancement of photocatalytic activities and revealed that the lanthanide ions were present as oxides on the surface of BiVO 4 .…”