Visible-light-driven decomposition of antibiotic oxytetracycline and disinfection of Escherichia coli using magnetically recyclable lanthanum-nitrogen co-doped titania/calcium ferrite/diatomite heterojunction material

Yan Chen,Qiong Wu,Jun Wang,Youtao Song 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.77 No.-

Powdery photocatalyst has shown great potential in wastewater treatment, yet the low reusability is stillits deficiency. In this work, we prepared magnetically recyclable lanthanum-nitrogen co-doped titania/CaFe2O4/diatomite (LN-TCD) ternary material by sol-gel technology. The photocatalytic activity of thismaterial was evaluated via the decomposition of antibiotic oxytetracycline and disinfection of bacteriaEscherichia coli under visible light. Charge transfer took place at the interface between titania andCaFe2O4, and improved the photocatalytic activity. The photodecomposition rate was accelerated by thehigh adsorption ability of substrate diatomite. The optimal preparation and experimental factors weredetermined, and the decomposition mechanism was proposed.

Preparation of ortho-symmetric double (OSD) Z-scheme SnO2\CdSe/ Bi2O3 sonocatalyst by ultrasonic-assisted isoelectric point method for effective degradation of organic pollutants

Siyi Li,Meng Zhang,Xue Ma,Jing Qiao,Hongbo Zhang,Jun Wang,Youtao Song 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.72 No.-

In this work, an ortho-symmetric double (OSD) Z-scheme SnO2\CdSe/Bi2O3 sonocatalyst is skillfullydesigned and synthesized via ultrasonic-assisted isoelectric point method and then the sonocatalyticactivity is studied under ultrasonic irradiation in the degradation of organic contaminants. The effects ofultrasonic irradiation time, sonocatalyst dosage, initial Rhodamine B concentration, organic dye kind andused times are investigated systemically. The formation of OH and h+ are confirmed by using t-BuOH andoxalate, respectively. The Rhodamine B can completely be degraded under given experimental conditionssuch as 10 mg/L Rhodamine B solution, 1.00 g/L OSD Z-scheme SnO2\CdSe/Bi2O3 dosage and 150 minultrasonic process. The formation of mainly intermediate products is studied by Liquid Chromatography–Mass Spectrometry. Moreover, the sonocatalytic reaction mechanism caused by OSD Z-schemeSnO2\CdSe/Bi2O3 is presented.

Photocatalytic conversion of nitrite in aqueous solution over nanocomposite photocatalyst Er3+:Y3Al5O12/BiPO4 using different photosources

Yidi Wang,Bowen Li,Guanshu Li,Yingying Huang,Dawei Fang,Jun Wang,Youtao Song 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.47 No.-

Three crystal phases of BiPO4 (HBIP, nMBIP and mMBIP), corresponding photocatalysts (Er3+:Y3Al5O12/HBIP, Er3+:Y3Al5O12/nMBIP and Er3+:Y3Al5O12/mMBIP) and their nanocomposite photocatalyst (Er3+:Y3Al5O12/(H-nM-mM)BIP) were prepared by hydrothermal, ultrasonic dispersion and liquid boilingmethods. The prepared photocatalysts were characterized by X-ray diffractometer (XRD), energydispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and UV–vis diffuse reflectancespectra (DRS). The catalytic activity of prepared photocatalysts was evaluated via photocatalyticconversion rate of nitrite under ultraviolet-light, visible-light and simulated solar-light irradiations. These three photocatalysts all exhibited excellent performance under simulated solar-light irradiationand reached 85.36%, 84.42% and 78.53% conversion rates, respectively, for Er3+:Y3Al5O12/mMBIP, Er3+:Y3Al5O12/nMBIP and Er3+:Y3Al5O12/HBIP. Particularly, Er3+:Y3Al5O12/(H-nM-mM)BIP was also found toplay a high catalytic activity, resulting in 78.68%, 70.04% and 82.57% conversion rates, respectively, underultraviolet-light, visible-light and simulated solar-light irradiation. In addition, the study of used timesshowed that the prepared photocatalysts can be effectively recycled without an apparent inactivation onthe photocatalytic activity. This research may provide a potential way for converting nitrite and othercontaminants by utilizing solar energy efficiently.

Preparation of new visible-light driven nanocomposite photocatalysts, X/NaTaO3/Er3+:YAlO3 (X = Ag, Au and Pt), for photocatalytic conversion of Cr(VI)

Bowen Li,Yidi Wang,Fangyuan Tian,Guanshu Li,Zhaohong Zhang,Jun Wang,Youtao Song 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-

In order to expand the light response range of wide band-gap semiconductor photocatalyst (NaTaO3) for effective photocatalytic conversion of Cr(VI), an up-conversion luminescence agent (Er3+:YAlO3) is combined with NaTaO3 and a visible-light driven photocatalyst, NaTaO3/Er3+:YAlO3, is prepared. Moreover, several conduction band co-catalysts (Ag, Au and Pt) are deposited the surface of NaTaO3/Er3+: YAlO3, respectively, to facilitate the transfer rate of photo-generated electrons. X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM) analyses are employed to confirm the morphology, microstructure and composition of the prepared photocatalysts. In addition, UV–vis diffuse reflectance spectra are determined to explore the visible-light absorption properties of Er3+:YAlO3, NaTaO3, NaTaO3/Er3+:YAlO3 and X/NaTaO3/Er3+:YAlO3 (X = Ag, Au and Pt). Photoluminescence (PL) spectra are used to estimate the recombination rate of electron–hole pairs. The effects of irradiation time, photosource kind, solution acidity and used times on the photocatalytic capabilities of NaTaO3/Er3+:YAlO3 and X/NaTaO3/Er3+:YAlO3 (X = Ag, Au and Pt) are investigated in detail. The results show that the uses of up-conversion luminescence agent (Er3+:YAlO3) and co-catalysts (Ag, Au and Pt) can promote NaTaO3 to utilize visible-light to carry out the photocatalytic conversion of Cr(VI). Particularly, the prepared Au/NaTaO3/Er3+:YAlO3 nanocomposite with 1.0 wt% Au and 0.3:1.0 molar ratio of Er3+:YAlO3 and NaTaO3 shows the highest photocatalytic activity in conversion of Cr(VI).

Three narrow band-gap semiconductors modified Z-scheme photocatalysts, Er3+:Y3Al5O12@NiGa2O4/(NiS, CoS2 or MoS2)/Bi2Sn2O7, for enhanced solar-light photocatalytic conversions of nitrite and sulfite

Xue Ma,Chunquan Wang,Guowei Wang,Guanshu Li,Siyi Li,Jun Wang,Youtao Song 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.66 No.-

Three Z-scheme photocatalysts, Er3+:Y3Al5O12@NiGa2O4/NiS/Bi2Sn2O7, Er3+:Y3Al5O12@NiGa2O4/CoS2/Bi2Sn2O7 and Er3+:Y3Al5O12@NiGa2O4/MoS2/Bi2Sn2O7, are designed for synchronous conversions of nitrite and sulfite and fabricated by sol-hydrothermal and calcination methods. In these Z-scheme photocatalysts, three narrow band-gap semiconductors as “conductive ladder” are inserted between Er3+:Y3Al5O12@NiGa2O4 and Bi2Sn2O7 to accelerate the electron transfer from conduction band of Bi2Sn2O7 to valence band of NiGa2O4. Er3+:Y3Al5O12 as an up-conversion luminescence agent (from visible-light to ultraviolet-light) provides enough ultraviolet-light for satisfying the energy demand of wide band-gap NiGa2O4. The prepared photocatalysts are characterized by UV–vis diffuse reflectance spectra (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffractometer (XRD), Fourier transform infrared (FT-IR) spectra and photoluminescence (PL) spectra. The photocatalytic activity of prepared photocatalysts is evaluated via conversions of nitrite and sulfite under simulated solar-light irradiation. The results show that the prepared Er3+:Y3Al5O12@NiGa2O4/NiS/Bi2Sn2O7, Er3+:Y3Al5O12@NiGa2O4/CoS2/Bi2Sn2O7 and Er3+:Y3Al5O12@NiGa2O4/MoS2/Bi2Sn2O7 composites exhibit the high and stable photocatalytic activity during the conversions of nitrite and sulfite. The highest conversion ratios (86.23% and 94.44%) for nitrite and sulfite can be obtained when the Er3+:Y3Al5O12@NiGa2O4/NiS/Bi2Sn2O7 is adopted as photocatalyst under simulated solar-light irradiation. Meanwhile, the effect of simulated solar-light irradiation time and corresponding reaction kinetics on photocatalytic conversions of nitrite and sulfite are also studied. Subsequently, the study of used times shows that the prepared Z-scheme photocatalysts can be effectively reused without an apparent inactivation on photocatalytic activity. These results demonstrate that the Er3+:Y3Al5O12@NiGa2O4/NiS/Bi2Sn2O7 is a potential Z-scheme photocatalyst to be used in actual conversions of nitrite and sulfite under solar-light irradiation.

A highly active Z-scheme NiGa2O4/anthraquinone/MoO3 photocatalyst via charge transfer for sunlight photocatalytic simultaneous conversions of nitrite and sulfite

Xue Ma,Siyi Li,Zhihui Qu,Meng Zhang,Jing Qiao,Xin Cui,Chunquan Wang,Jun Wang,Youtao Song 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.78 No.-

The separation efficiency of photogenerated electron-hole pairs (e –h+) is an important factor for ahighly photocatalytic activity of Z-scheme photocatalytic system. In order to suppress the recombining ofphotogenerated e and h+ and enhance the electron transfer rate, anthraquinone (AQ) as special electrontransfer channel is combined with NiGa2O4 and MoO3, forming a Z-scheme NiGa2O4/AQ/MoO3photocatalyst. Due to unique chemical and physical properties, AQ provides a novel electron transmissionway. Compared with traditional conductive channels (for example, noble metals and graphene), in thisway, the AQ may greatly enhance the electron transfer efficiency. In addition, the related morphology,optical properties and chemical composition were investigated by a sequence of characterizationmethods. The influences of photocatalyst species, irradiation time and used times in simultaneouslyconverting nitrite and sulfite under simulated sunlight were also studied. The results indicate that theprepared Z-scheme NiGa2O4/AQ/MoO3 photocatalyst exhibits a much high activity. The conversion ratesof nitrite and sulfite can reach 89.81% and 94.47%, respectively, under simulated sunlight irradiation forfour hours. The enhanced photocatalytic activity is attributed to the fact that AQ can rapidly transferelectron by inner charge transfer. This charge transfer way can provide a new idea to design subsequentphotocatalysts.