Enhanced Visible Light-Driven Photocatalytic Activities and Photoluminescence Characteristics of BiOF Nanoparticles Determined via Doping Engineering

Abstract

We report a new type of highly efficient visible light-driven photocatalyst, Sm3+-activated BiOF nanoparticles, developed by a facile solid-state reaction technology. The corresponding phase compositions, morphological nature, and chemical states along with complementary theoretical calculation insights are investigated systematically. Upon 404 nm laser excitation, the photoluminescence performance of the synthesized nanoparticles is explored and the optimal properties are achieved in BiOF:xSm3+ (x = 0.07). The dipole–quadrupole interaction is attributed to the concentration quenching mechanism. Under visible light irradiation, the degradation of the RhB dye by utilizing the Sm3+-activated BiOF nanoparticles is studied. In comparison with the BiOF nanoparticles, the resultant compounds doped with Sm3+ ions demonstrate improved photocatalytic performance. Moreover, on the basis of density functional theory, the electronic structure of the BiOF impacted by Sm3+ ion doping is studied in detail by first-principles calculations, revealing the generation of an impurity energy level that is beneficial for enhancing the photocatalytic properties. Importantly, the h+ and •O2 – active species play a deterministic role in promoting the degradation of the RhB dye. Compared to commercial ZnO nanoparticles, the developed nanoparticles exhibit superior photocatalytic activities, further elaborating that the Sm3+-activated BiOF nanoparticles are poised to be one of most promising visible light-driven photocatalyst candidates.

Facile Realization of Boosted Near‐Infrared‐Visible Light Driven Photocatalytic Activities of BiOF Nanoparticles through Simultaneously Exploiting Doping and Upconversion Strategy

“…As shown in Figure 3a, there are two intense peaks at 158.9 and 164.2 eV which are assigned to the Bi 3+ 4f 7/2 and Bi 3+ 4f 5/2 , respectively. [18] Note that, the XPS spectrum of O 2− 1s is asymmetric and it is able to be deconvoluted into two separate bands with the central binding energy at 529.5 and 530.8 eV corresponding to the O 2− 1s and oxygen vacancy, [18,30] respectively, as displayed in Figure 3b. On the basis of previous literatures, [18,30] it is clear that the oxygen vacancy benefits promoting the light absorption capacity of photocatalyst in visible region, leading to the boosted photocatalytic performance.…”

“…BiOF pertains to direct semiconductor with an energy band gap (i.e., E g ) of 3.197 eV. [18] Interestingly enough, with the introduction of Er 3+ and Yb 3+ ions, both the Er 3+ -doped BiOF and Er 3+ / Yb 3+ -codoped BiOF compounds change to indirect semiconductors, in which the positions of the bottom of the conduction band (CB) and top of the valence band (VB) are inconsistent, and their E g values are found to be 3.12 and 3.10 eV, respectively, as displayed in Figure 4a,b. As is known, when the positions of the bottom of VB and the top of CB are inconsistent, the separation of the hole-electron pairs will be boosted which is help for achieving increasing the photocatalytic performance.…”

“…From Figure S4a, Supporting Information, one observes an intense absorption band, which originates from the charge transfer transitions of O 2− /F − → Bi 3+ , in the range of 250-450 nm. [18,30] Note that, when the dopants (i.e., Er 3+ and Yb 3+ ) are added, some sharp absorption bands arising from Er 3+ ions are also detected in the UV-vis absorption spectra aside from the intense absorption band, as depicted in Figure S4b-f [38] Aside from these sharp absorption bands, a red shift is also gained in the absorption edge of the resultant nanoparticles with the addition of the Yb 3+ ions (see Figure S4, Supporting Information), which is conducive to promoting their light capture capacities as well as improving the photocatalytic activities. Herein, due to the limitation of device, we cannot measure the characteristic peak of Yb 3+ ions since its absorption band located at around 980 nm.…”

“…[17] As a member of bismuth containing semiconductors, the investigation on the photocatalytic properties of BiOX (X = F, Cl, Br, and I), which displays unique matlockite structure with [XBiOOBiX] layers, has been intensively performed. [18,19] Particularly, with the help of weak nonbonding van der Waals interaction along the c-axis, [Bi 2 O 2 ] 2+ slabs with positive valence are interleaved by means of two halide ions, leading to the production of internal electric field along the caxis. [18] Note that, the occurrence of the internal electric field enables the separation of electron-hole pairs more efficiently which gives rise to admirable photocatalytic behaviors of BiOX.…”

Ce3+/Tb3+‐coactived NaMgBO3 phosphors toward versatile applications in white LED, FED, and optical anti‐counterfeiting

“…Based on the previous report, with increasing the temperature, the absorbance of samples would decrease, resulting in thermal degradation and luminescence quenching 54 . To further comprehend the thermal stability of NaMgBO 3 :0.01Ce 3+ ,0.03Tb 3+ sample, the activation energy was calculated by the Arrhenius equation: 55,56 where Δ E represents the activation energy, k is the Boltzmann constant, and A stands for the coefficient. I 0 and I are initial emission intensity and emission intensity at temperature T , respectively.…”