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Spray pyrolysis synthesis of mesoporous TiO2 microspheres and their post modification for improved photocatalytic activity
摘要： Mesoporous TiO2 microspheres were prepared by spray pyrolysis for photocatalysis. Post modification of TiO2 by heat treatment was performed to optimize its photocatalytic performance. First, spherical TiO2 particles with mesoporous structure were synthesized at pyrolysis temperatures of 500, 600, and 700 oC. After characterization by XRD, SEM, and N2 adsorption, a sample prepared at 500 oC was found to possess desirable properties for photocatalytic performance through post-modification. In methylene blue degradation, mesoporous TiO2 microspheres synthesized at 500 oC outperformed other microspheres. Furthermore, samples obtained by spray pyrolysis at 500 oC were calcined at various temperatures as a post-modification process. The sample calcined at 350 oC showed improved photocatalytic activity due to optimal anatase crystallinity and surface area.
关键词： Spray Pyrolysis,MB Degradation,Post Modification,Mesoporous TiO2 Spheres
更新于2025-11-21 10:59:37
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Platinum-enhanced amorphous TiO2-filled mesoporous TiO2 crystals for the photocatalytic mineralization of tetracycline hydrochloride
摘要： The adsorption ability and photoactivity of a photocatalyst largely determine the mineralization efficiency of antibiotics. Herein, aiming to enhance the adsorption and mineralization of antibiotics, we constructed a hierarchical porous core-shell structure by filling amorphous TiO2 in the pores of Pt-doped mesoporous TiO2 crystals (MCs). The physical–chemical properties of the prepared samples were investigated by surface photovoltage spectroscopy, X-ray photoelectron spectroscope, etc. Adsorption and photocatalysis experiments were conducted with tetracycline hydrochloride as the model antibiotic. Pt nanoparticles doped at the interface of the rutile-amorphous homojunction remarkably enhanced the built-in electric field. The enhanced electric field increased the hole transfer to the catalyst surface, and the Pt doping treatment promoted the growth of amorphous TiO2 into the mesopores of the MCs. The optimization increased the surface area of the catalyst without increasing the thickness of the amorphous TiO2 shell, thereby reducing the charge migration distance from the core–shell interface to the catalyst surface. The adsorption amount and mineralization efficiency of tetracycline hydrochloride for the porous core-shell composite were 6.7 and 3.8 times of those for MCs, respectively.
关键词： Crystal,Amorphous TiO2,TCH,Mesoporous TiO2,SPV,Charge carriers
更新于2025-11-14 17:04:02
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Synthesis of visible light responsive iodine-doped mesoporous TiO2 by using biological renewable lignin as template for degradation of toxic organic pollutants
摘要： The visible light responsive I-doped mesoporous TiO2 (I/TiO2-T) catalysts were synthesized by facile hydrolysis method with lignin as a template. The resulting I/TiO2-T catalysts synthesized from different amounts of I as a dopant and lignin as a template were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-Vis diffuse spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL), and electrochemical impedance spectroscopy (EIS). The photocatalytic activities of the resulting catalysts were investigated by the degradation of p-chlorophenol under artificial visible light irradiation. The results showed that the lignin-templated TiO2 with a suitable amount of I-doping (I/TiO2-T) had higher catalytic activity than the catalyst prepared form I-doped TiO2 without lignin template (I/TiO2). Complete degradation of p-chlorophenol was achieved by I/TiO2-T with suitable amount of I-doping at 60 min. However, 95.7, 10.7, and 5.5% of the p-chlorophenol was degraded with I/TiO2, TiO2-T, and P25 catalysts, respectively, under 140 min visible light irradiation. The enhanced catalytic activities of the samples with template and I-doping may be due to the small grain size and high specific surface area of the catalysts. The band gap and the electrical properties of TiO2 also could be adjusted with I-doping. The I-doped TiO2 with the extrinsic I5+-to-Ti4+ and the iodine-to-oxygen donor defects could be excited by visible irradiation for efficient pollutants degradation. A possible photocatalytic mechanism for the degradation of the pollutants with I/TiO2-T under visible light irradiation was also proposed.
关键词： Mesoporous TiO2,Visible light,I-doped,Lignin template
更新于2025-11-14 17:03:37
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Improved charge separation of NiS nanoparticles modified defect-engineered black TiO2 hollow nanotubes for boosting solar-driven photocatalytic H2 evolution
摘要： NiS nanoparticles (NPs) modified black TiO2 hollow nanotubes (NBTNs) are successfully synthesized via surface hydrogenation and facile solvothermal method. The unique structure with intensified surface and interface characteristic endow NBTNs with more catalytic sites, and increase charge carrier separation efficiency with a extended charge lifetime, overwhelmingly promoting its photocatalytic performance. The resultant NBTNs possess a relatively high surface area and pore size of ~89 m2 g-1 and ~9.8 nm, respectively. The resultants NBTNs exhibit an excellent solar-driven photocatalytic hydrogen rate (3.17 mmol h-1 g-1), which almost as high as that of Pt as cocatalyst, in which the apparent quantum (AQE) yield of 5.4 % (420 nm) is recorded for the NBTNs sample. Moreover, the turnover number (TON) can be up to 116000 within 48 h. And the turnover frequency (TOF) is 2400 for NiS. This novel strategy could provide a better understanding of cocatalyst photocatalytic mechanism, and a scheme simultaneously regulating the morphology and structure of photocatalyst for promoting H2 generation.
关键词： Mesoporous TiO2 nanotube,Oxygen vacancy defect,NiS cocatalyst,Photocatalysis,Ti3+ self-doping
更新于2025-09-23 15:23:52
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Mechanisim investigation on the enhanced and selective photoelectrochemical oxidation of atrazine on molecular imprinted mesoporous TiO2
摘要： In this work, enhanced and selective photoelectrochemical (PEC) oxidation of atrazine was realized on molecular imprinted mesoporous TiO2 (MI-meso-TiO2). The investigation revealed that, for one hand, the surface MI sites could function as surface defects for accelerating the separation of photogenerated holes and electrons, leading to enhanced generation of hydroxyl radicals. For the other hand, the MI sites showed enhanced binding affinity toward atrazine, resulted from the formation of multiple hydrogen bonds and halogen bonds etc., which was testified by in situ ATR-FTIR spectra. It led to the enhanced adsorption and improved local concentration of atrazine on the electrode surface. Both the two factors contributed to the improved PEC oxidation activity for atrazine on MI-meso-TiO2 compared with that on meso-TiO2. Moreover, the high binding affinity between MI sites and atrazine resulted in the selective recognition ability toward atrazine in the presence of the coexisting pollutants, so that selective PEC oxidation of atrazine in complex polluted water samples was successfully achieved on MI-meso-TiO2 with the apparent rate constant of 0.25 h-1, whereas that on meso-TiO2 was only 0.08 h-1. This work provided something new for explaining the selective and enhanced PEC performance on molecular imprinting catalyst.
关键词： mesoporous TiO2,molecular imprint,selective photoelectrochemical oxidation,atrazine
更新于2025-09-23 15:22:29
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Using soft polymer template engineering of mesoporous TiO <sub/>2</sub> scaffolds to increase perovskite grain size and solar cell efficiency
摘要： The mesoporous (meso)-TiO2 layer is a key component of high efficiency perovskite solar cells (PSCs). Herein, pore size controllable meso-TiO2 layers are prepared using spin coating of commercial TiO2 nanoparticle (NP) paste with added soft polymer templates (SPT) followed by removal of the SPT at 500 °C. The SPTs consist of swollen crosslinked polymer colloids (microgels, MGs) or a commercial linear polymer (denoted as LIN). The MGs and LIN were comprised of the same polymer, which was poly(N-isopropylacrylamide) (PNIPAm). Large (L-MG) and small (S-MG) MG SPTs were employed to study the effect of template size. The SPT approach enabled pore size engineering in one deposition step. The SPT/TiO2 nanoparticle films had pore sizes > 100 nm; whereas, the average pore size was 37 nm for the control meso-TiO2 scaffold. The largest pore sizes were obtained using L-MG. SPT engineering increased the perovskite grain size in the same order as the SPT sizes: LIN < S-MG < L-MG and these grain sizes were larger than obtained using the control. The power conversion efficiencies (PCEs) of the SPT/TiO2-devices were ~ 20% higher than that for the control meso-TiO2 device and the PCE of the champion S-MG device was 18.8%. The PCE improvement is due to the increased grain size and more effective light harvesting of the SPT devices. The increased grain size was also responsible for the improved stability of the SPT/TiO2 devices. The SPT method used here is simple, scalable and versatile and should also apply to other PSCs.
关键词： Perovskite solar cells,template engineering,mesoporous TiO2,porosity,microgel,grain size.
更新于2025-09-23 15:21:01
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Enhanced photocatalytic activity under visible light by the synergistic effects of plasmonics and Ti3+-doping at the Ag/TiO2- heterojunction
摘要： A heterojunction of plasmonic Ag particles on Ti3+-doped macro-/meso-porous TiO2 framework consisting of parallel microchannels, denoted as Ag/TiO2-x, has been fabricated by a simple microwave-assisted process employing vitamin C as the reducing agent for forming TiO2-x framework followed by photochemical deposition of Ag particles. Charge transport and recombination processes were detected through transient photocurrent responses. The visible-light photocatalytic hydrogen production rate and the apparent reaction rate constant of RhB photodegradation with 3%-Ag/TiO2-x catalyst are about 5.3 and 14.0 fold higher than those with the pristine macro-/meso-porous TiO2 framework, respectively. A mechanism based on the synergistic effects of Ag plasmonics and Ti3+-doping at the Ag/TiO2-x heterojunction is proposed, which consistently explains the high photocatalytic performance in hydrogen evolution and the improved photocatalytic decomposition of RhB under visible light. This study demonstrates the effective route to synthesize new heterojunction photocatalytic materials with multifunctional properties using low-cost and rapid microwave processes.
关键词： Macroporous/mesoporous TiO2 microchannel,Ag/TiO2-x heterojunction,Ti3+-doped TiO2,Photocatalysis,Surface plasmon resonance
更新于2025-09-23 15:19:57
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Surface Engineering of Low-Temperature Processed Mesoporous TiO <sub/>2</sub> via Oxygen Plasma for Flexible Perovskite Solar Cells
摘要： A major problem in the application of mesoporous TiO2 as an electron transport layer for flexible perovskite solar cells is that a high temperature sintering process is required to remove organic additives from the TiO2 layer. A facile oxygen plasma process is herein demonstrated to fabricate mesoporous structured perovskite solar cells with significant photovoltaic performance at low temperatures. When the low-temperature processed TiO2 layer is modified via oxygen plasma, the organic additives in the TiO2 layer that hinder the charge transport process are successfully decomposed. The oxygen plasma treatment improves the wettability and infiltration of the perovskite layer and also passivates the oxygen vacancy related traps in TiO2. Hence, the oxygen plasma treatment evidently enhances charge extraction and transport, thereby improving photovoltaic performance and decreasing hysteresis.
关键词： Mesoporous TiO2,Flexible solar cell,Oxygen plasma,Low-temperature processed TiO2,Perovskite solar cell
更新于2025-09-23 15:19:57
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Enhanced photocatalytic activity of a mesoporous TiO2 aerogel decorated onto three-dimensional carbon foam
摘要： TiO2/carbon composites have been well studied as solar-light photocatalysts because they combine the advantages of TiO2 (good photocatalytic activity) and carbon (enhanced charge carrier separation). Mesoporous TiO2 aerogels are fragile by nature and the addition of free-standing three-dimensional (3D) porous carbon foam (CF) not only makes it easy for separation and collection after photocatalytic treatment but also acts as a scaffold for the long-term application of TiO2 aerogels in the photocatalysis. Hence, recent reports have shown that mesoporous TiO2 aerogel/CF composites synthesized by the carbonization of a polymer followed by using the sol-gel method are significant for use in photocatalysis applications. In addition, the 3D macroporous CF not only acts as a support for TiO2 aerogels but also improves the efficiency of light use and extends the photoresponse of TiO2 to the visible region. The TiO2 aerogel was homogeneously distributed onto the 3D CF because of the vacuum infiltration used during the synthesis of the composites. The simulated solar-light irradiated photocatalytic degradation of Rhodamine B organic pollutant was used to evaluate the TiO2 aerogel/CF composite catalysts, which was higher than with a pristine TiO2 aerogel. This facile synthesis approach for 3D foam type TiO2/carbon composites could be useful in the treatment of wastewater.
关键词： anatase,Mesoporous TiO2 aerogel,photocatalysis,sol-gel method,carbon foam
更新于2025-09-23 15:19:57
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Real time nanoplasmonic sensing for monitoring CH <sub/>3</sub> NH <sub/>3</sub> PbI <sub/>3</sub> perovskite formation in mesoporous TiO <sub/>2</sub> films
摘要： The formation of methylammonium lead iodide (CH3NH3PbI3) perovskite into mesoporous titania (TiO2) scaffold via a sequential deposition method is known to offer high quality films for good photovoltaic device performance. The local kinetics at the lower interface between the mesoporous TiO2 film and the collecting electrode govern perovskite growth and formation. Here, we have used a NanoPlasmonic Sensing (NPS) approach with gold (Au) nanosensors to monitor the formation of CH3NH3PbI3 perovskite at the lower interface of up to 650 nm mesoporous TiO2 films. This technique provides time-resolved spectral shifts of the localized surface plasmon resonance at different operating temperatures and methylammonium iodide (CH3NH3I3) concentrations by recording changes in the local vicinity of the Au nanosensors at the mesoporous TiO2 film interface. Analytical studies included ellipsometry, scanning electron microscopy, X-ray diffraction, and photoluminescence spectroscopy. The results show that both the intensity of the NPS response and NPS rate constants are correlated with the operating concentrations and temperatures of CH3NH3I3 as well as CH3NH3PbI3 perovskite growth in mesoporous TiO2.
关键词： nanoplasmonic sensing,localized surface plasmon resonance,mesoporous TiO2 films,perovskite formation,CH3NH3PbI3
更新于2025-09-16 10:30:52