JOURNAL OF RARE EARTHS
·
2021
·
IF 3.712
Zhimin Zhao,Jinjia Liu,Gala Sa,Aiju Xu
In this study, the photocatalytic activity of Nd-TiO 2 photocatalysts obtained by common hydrothermal method was evaluated by practical experiments and theoretical calculations based on density functional theory (DFT). The synthesized photocatalysts were characterized by X-ray diffraction (XRD), N 2 adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV–Vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) to study their physical/chemical properties. At the same time, the photoelectronic performance was also investigated. The photodegradation ability of as-prepared photocatalysts and the effect of Nd doped amount and photocatalysts dosage were investigated by the photodegradation of phenol (30 mg/L) under 400 W metal halide lamp (UV–Vis). The effect of Nd on electronic properties of TiO 2 and adsorption ability of phenol were discussed. Results show the red-shift wavelength of 0.5 mol%Nd-TiO 2 , indicating that its absorption capacity is stronger than pristine TiO 2 in the same wavelength range. The result of DFT calculations demonstrates that the optical bandgap of Nd-TiO 2 is profoundly reduced, thus the light absorption ability is promoted, which will be responsible for the enhanced photocatalytic performance of Nd-TiO 2 . 0.5 mol% Nd is an optimum value for photodegradation phenol, and phenol can be completely degraded by 0.5 mol%Nd-TiO 2 for 210 min, the higher catalytic performance is derived from the efficient separation of e – /h + pairs. Moreover, the adsorption energy calculations of phenol on TiO 2 (101) and Nd-TiO 2 (101) demonstrate that the Nd doping can significantly enhance the adsorption ability of phenol on catalyst surfaces because of the formation of Nd–O bonds. At last, the stability measurement through four recycles exhibits that 0.5 mol%Nd-TiO 2 possesses excellent stability.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2021
·
IF 3.196
Jinlong Li,Boxin Li,Guozhe Sui,Lijuan Du,Yan Zhuang,Yulin Zhang,Yuanfang Zou
Volatile organic compounds (VOCs) with toxicity properties discharged from industrial emissions and combustion engines threaten human health and cause environmental problems. Therefore, it is important to develop technologies to remove VOCs from air. In this study, the performance of Nd (neodymium) -TiO 2 nanoparticles embedded in a supported ionic liquid membrane (SILM) for removal of VOCs from air was investigated. Aiming at functionalizing the ionic liquid membrane with photocatalytic capability, we developed a facile and effective approach for the removal of VOCs by coupling highly efficient photocatalysts with the SILM. Nd-TiO 2 nanoparticles , which are ultraviolet-visible (UV–Vis) light-driven photocatalysts, were prepared by sol-gel and immersed in the SILM for use as a photocatalytic membrane-based reactor. The gaseous VOCs tested were toluene, acetone, chloroform, benzene, and xylene. We confirmed that at a loading of 50 wt% Nd-TiO 2 nanoparticles (1 wt% Nd content) and 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMI m ]PF 6 ) as SILM ([HMI m ]PF 6 /Nd-TiO 2 SILM), the as-prepared photocatalytic membrane-based reactor exhibited higher removal efficiency of VOCs from air (60~80% removal after 10 h) under UV–Vis light illumination than individual SILM or photocatalytic systems. Effluent gas analysis revealed that 25–55% of VOCs was decomposed and mineralized in the photocatalytic membrane reactor, which exhibited higher VOCs removal efficiency than membrane separation. These results indicate that the photocatalytic membrane-based reactor containing Nd-TiO 2 nanoparticles and SILM designed in this study is highly active and stable. This study on [HMIm]PF 6 /Nd-TiO 2 SILM was initiated to couple membrane separation with photocatalytic degradation of gaseous VOCs and can serve as a promising way for eliminating harmful VOCs with low concentration from air.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Huining Huang,Huiliang Li,Zeyan Wang,Peng Wang,Zhaoke Zheng,Yuanyuan Liu,Ying Dai,Yingjie Li,Baibiao Huang
In this work, we fabricated NaYF 4 :Yb 3+ ,Tm 3+ @NaYF 4 :Yb 3+ ,Nd 3+ @TiO 2 (Tm@Nd@TiO 2 ) core@shell nanoparticles and investigated their near-infrared (NIR) photocatalytic activities. Comparing to traditional TiO 2 based upconversion (UC) photocatalysts (i.e., NaYF 4 :Yb 3+ ,Tm 3+ @TiO 2 , named Tm@TiO 2 ), Tm@Nd@TiO 2 exhibits enhanced photocatalytic activity under NIR light irradiation. The photocatalytic activity of Tm@Nd@TiO 2 under 980, 808, and 980 + 808 nm laser irradiation is 4.40, 5.84, and 9.83 times as high as that of Tm@TiO 2 under only 980 nm irradiation, respectively. The ethylene degradation rate of Tm@Nd@TiO 2 under 980 + 808 nm laser irradiation is 6.4 times as that of Tm@TiO 2 . The photocatalytic activity of Tm@Nd@TiO 2 under visible + NIR irradiation is even comparable with (∼2/3) that under UV light irradiation during Rhodamine B (RhB) degradation. The enhanced photocatalytic activity of Tm@Nd@TiO 2 can be attributed to the stronger light absorption in NIR region ascribed to Nd 3+ , lower water absorption and the enhanced UC emission of Tm@Nd with unique core@shell nanostructures. This work can provide a possible route to improve the NIR photocatalytic activity and stimulate the applications in many other fields.
研究领域:
材料科学
·
光催化技术
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 8
·2063
·
IF 5.076
Zihao Zhao,Xiang Zhao,Mu Zhang,Xudong Sun
Surface-enhanced Raman scattering (SERS) for semiconductor nanomaterial systems is limited due to weak Raman signal intensity and unclear charge-transfer (CT) processes for chemical enhancement. Here, rare-earth element neodymium-doped titanium dioxide (Nd-TiO2) nanoparticles (NPs) were synthesized by the sol–gel method. The characterizations show that the doping of Nd ions causes TiO2NPs to show an increase in the concentration of defects and change in the energy level structure. The CT process between Nd-TiO2NPs substrate and probe molecule 4-Mercaptopyridine (4-Mpy) was innovatively analyzed using the relative energy level location relationship of the Dorenbos model. The SERS signal intensity exhibits an exponential enhancement with increasing Nd doping concentration and reaches its optimum at 2%, which is attributed to two factors: (1) The increase in the defect concentration is beneficial to the CT process between the TiO2and the probe molecule; (2) the introduction of 4felectron orbital energy levels of rare-earth ions created unique CT process between Nd3+and 4-Mpy. Moreover, the Nd-TiO2NPs substrate shows excellent SERS performance in Raman signal reproducibility (RSD = 5.31%), the limit of detection (LOD = 10−6M), and enhancement factor (EF = 3.79 × 104). Our work not only improves the SERS performance of semiconductor substrates but also provides a novel approach to the development of selective detection of probe molecules.
研究领域:
材料科学
·
光谱学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Yuxian Su,Li Liu,Shipeng Wen
Semiconductor photocatalysis is a promising strategy for wastewater treatment. However, a limited photoresponse range, rapid recombination of photoinduced charge carriers, poor stability, and other problems have posed obstacles to practical applications. Herein, a facile strategy to fabricate a near-infrared-driven broadband photocatalyst was developed by anchoring the core–shell nanostructure of NaYF4:Yb,Tm@NaYF4:Yb,Nd@TiO2 (Tm@Nd@TiO2) onto the surface of porous silica/carbon (mSC) electrospun fibers. The Tm@Nd@TiO2 nanoparticles (NPs) exhibited strong near-infrared light absorption and energy transfer from the NaYF4:Yb,Tm@NaYF4:Yb,Nd core to the TiO2 shell, triggering the photocatalytic reaction. In addition, the interconnected mesoporous structure and carbon network of Tm@Nd@TiO2/mSC was found to be beneficial in improving the adsorption capacity toward organic pollutants, promoting the separation of photogenerated carriers, and further improving the overall photocatalytic performance. The photocatalytic activity of Tm@Nd@TiO2/mSC nanocomposite was evaluated by degrading methyl orange solution in the visible-near-infrared and simulated sunlight regions. The Tm@Nd@TiO2/mSC nanocomposite exhibited excellent adsorption performance. The photocatalytic activity of Tm@Nd@TiO2/mSC was found to be 3 times higher than that of bare Tm@Nd@TiO2 over 60 min.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）