Optimization of N doping in TiO2 nanotubes for the enhanced solar light mediated photocatalytic H2 production and dye degradation

Divyasri, Yadala Venkata; Reddy, N. Lakshmana; Lee, Ki-Young; Sakar, M.; Rao, Vempuluru Navakoteswara; Venkatramu, V.; Shankar, M.V.; Reddy, N. C. Gangi

doi:10.1016/j.envpol.2020.116170

Cited by 67 publications

(28 citation statements)

References 75 publications

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“…As in many other environmental and energy applications, titanium dioxide has been the photocatalyst more widely used for the conversion of CO 2 to fuel, mainly due to its photoactivity, high stability, low cost, and safety [ 3 , 4 ]. However, its application is limited because of its relative wide band gap (3–3.2 eV) and rapid recombination rate of photo-induced electron-hole pairs [ 5 ]. To overcome these drawbacks, different strategies have been proposed, such as doping with transition metal cations [ 6 ], using enhanced geometries [ 7 ] or photocatalyst supporting on carbon materials [ 8 , 9 ].…”

Section: Introductionmentioning

confidence: 99%

“…Compared with metal doping, non-metal dopants lead to catalysts with higher photo-stability, less environmental contamination, and lower cost [ 10 ]. Particularly, doping with N atoms into the TiO 2 lattice structure leads to the generation of N 2p energy levels near to the valence band (VB) of TiO 2 , thus reducing its band gap and extending semiconductor light absorption to the visible spectrum [ 5 ]. Moreover, N atoms also prevent the recombination of charge carriers in N-doped TiO 2 and can form metastable centers due to their stability, low ionization potential and having an atomic radius comparable with oxygen [ 5 ].…”

Section: Introductionmentioning

confidence: 99%

“…Particularly, doping with N atoms into the TiO 2 lattice structure leads to the generation of N 2p energy levels near to the valence band (VB) of TiO 2 , thus reducing its band gap and extending semiconductor light absorption to the visible spectrum [ 5 ]. Moreover, N atoms also prevent the recombination of charge carriers in N-doped TiO 2 and can form metastable centers due to their stability, low ionization potential and having an atomic radius comparable with oxygen [ 5 ]. However, the increases achieved in visible light absorption and lifetime of the electron-hole pairs photogenerated with this catalytic material are still limited.…”

Section: Introductionmentioning

confidence: 99%

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Photocatalytic Reduction of CO2 with N-Doped TiO2-Based Photocatalysts Obtained in One-Pot Supercritical Synthesis

et al. 2022

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The objective of this work was to analyze the effect of carbon support on the activity and selectivity of N-doped TiO2 nanoparticles. Thus, N-doped TiO2 and two types of composites, N-doped TiO2/CNT and N-doped TiO2/rGO, were prepared by a new environmentally friendly one-pot method. CNT and rGO were used as supports, triethylamine and urea as N doping agents, and titanium (IV) tetraisopropoxide and ethanol as Ti precursor and hydrolysis agent, respectively. The as-prepared photocatalysts exhibited enhanced photocatalytic performance compared to TiO2 P25 commercial catalyst during the photoreduction of CO2 with water vapor. It was imputed to the synergistic effect of N doping (reduction of semiconductor band gap energy) and carbon support (enlarging e−-h+ recombination time). The activity and selectivity of catalysts varied depending on the investigated material. Thus, whereas N-doped TiO2 nanoparticles led to a gaseous mixture, where CH4 formed the majority compared to CO, N-doped TiO2/CNT and N-doped TiO2/rGO composites almost exclusively generated CO. Regarding the activity of the catalysts, the highest production rates of CO (8 µmol/gTiO2/h) and CH4 (4 µmol/gTiO2/h) were achieved with composite N1/TiO2/rGO and N1/TiO2 nanoparticles, respectively, where superscript represents the ratio mg N/g TiO2. These rates are four times and almost forty times higher than the CO and CH4 production rates observed with commercial TiO2 P25.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Photocatalytic Reduction of CO2 with N-Doped TiO2-Based Photocatalysts Obtained in One-Pot Supercritical Synthesis

et al. 2022

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“…These toxic and dangerous substances are harmful and cannot be removed through conventional methods such as physical adsorption and biochemical techniques [ 4 ]. Thus, a suitable alternative approach such as advanced oxidation processes (AOPs) has been developed [ 5 , 6 , 7 , 8 , 9 ]. Semiconductors illuminated with UV or solar light (or any other strong light source), causes a valence electron to move to the conduction band, leaving a hole in the valence band.…”

Section: Introductionmentioning

confidence: 99%

Design and Preparation of Biomass-Derived Activated Carbon Loaded TiO2 Photocatalyst for Photocatalytic Degradation of Reactive Red 120 and Ofloxacin

et al. 2022

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The design and development of novel photocatalysts for treating toxic substances such as industrial waste, dyes, pesticides, and pharmaceutical wastes remain a challenging task even today. To this end, a biowaste pistachio-shell-derived activated carbon (AC) loaded TiO2 (AC-TiO2) nanocomposite was fabricated and effectively utilized towards the photocatalytic degradation of toxic azo dye Reactive Red 120 (RR 120) and ofloxacin (OFL) under UV-A light. The synthesized materials were characterized for their structural and surface morphology features through various spectroscopic and microscopic techniques, including high-resolution transmission electron microscope (HR-TEM), field emission scanning electron microscope (FE-SEM) along with energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, photoluminescence spectra (PL) and BET surface area measurements. AC-TiO2 shows enhanced photocatalytic activity compared to bare TiO2 due to the change in the bandgap energy and effective charge separation. The degradation rate of dyes was affected by the bandgap of the semiconductor, which was the result of the deposition weight percentage of AC onto the TiO2. The presence of AC influences the photocatalytic activity of AC-TiO2 composite towards RR 120 and OFL degradation. The presence of heteroatoms-enriched AC enhances the charge mobility and suppresses the electron-hole recombination in AC-TiO2 composite, which enhances the photocatalytic activity of the composite. The hybrid material AC-TiO2 composite displayed a higher photocatalytic activity against Reactive Red 120 and ofloxacin. The stability of the AC-TiO2 was tested against RR 120 dye degradation with multiple runs. GC-MS analyzed the degradation intermediates, and a suitable degradation pathway was also proposed. These results demonstrate that AC-TiO2 composite could be effectively used as an ecofriendly, cost-effective, stable, and highly efficient photocatalyst.

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“…This method is more economical and reasonable because of the easy availability of sufficient quantity of sea water. In this regard, TiO 2 has been extensively used over the last few decades because of its high chemical stability, nontoxic nature, economical and easy availability [1][2][3]. However, use of TiO 2 is only effective towards the utilization of the UV light in the solar spectrum, and it suffers with high recombination rate of photogenerated electrons and holes, which leads to a low quantum yield and poor photocatalytic activity [4].…”

Section: Introductionmentioning

confidence: 99%

Efficient photocatalytic hydrogen production over Ce/ZnO from aqueous methanol solution

Patil

Jadhav

Bhoir

2021

Mater Renew Sustain Energy

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Ce/ZnO crystallites along with bare ZnO were prepared by solution free mechanochemical method and characterized with powder XRD, SEM, EDX, XPS, UV–Visible and Photoluminescence (PL) spectra. The visible light photocatalytic performance of these materials was investigated for H2 evolution with the aqueous 10vol% methanol solution under one sun conditions using solar simulator. X-ray diffraction data suggests the hexagonal wurtzite structure for Ce/ZnO crystallites and the incorporation of Ce4+ ion in ZnO is supported by the shifting of XRD peaks to lower Bragg angles that indicate lattice expansion. With the increase of Ce content in ZnO, the crystallite size of Ce/ZnO decreases and the specific surface area increases. UV–Visible spectra propose the decrease in optical band gap of Ce incorporated ZnO with the increase of Ce content up to 3 mol. %. The XPS analysis supports the incorporation of Ce4+ in Ce/ZnO. The PL spectra propose that, with the insertion of Ce ions into ZnO, intensity of UV emission band decreases that reflects the low recombination rate of photogenerated charge carriers, which is responsible for higher photocatalytic H2 production. The extent of hydrogen production is affected by calcination temperature of Ce/ZnO. 2 mol. % Ce incorporated ZnO calcined at 600 °C produces43 μmolh−1 g−1 of hydrogen.

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Optimization of N doping in TiO2 nanotubes for the enhanced solar light mediated photocatalytic H2 production and dye degradation

Cited by 67 publications

References 75 publications

Photocatalytic Reduction of CO2 with N-Doped TiO2-Based Photocatalysts Obtained in One-Pot Supercritical Synthesis

Photocatalytic Reduction of CO2 with N-Doped TiO2-Based Photocatalysts Obtained in One-Pot Supercritical Synthesis

Design and Preparation of Biomass-Derived Activated Carbon Loaded TiO2 Photocatalyst for Photocatalytic Degradation of Reactive Red 120 and Ofloxacin

Efficient photocatalytic hydrogen production over Ce/ZnO from aqueous methanol solution

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