BACKGROUND Accurate diagnosis and early resection of colorectal polyps are important to prevent the occurrence of colorectal cancer.However,technical factors and morphological factors of polyps itself can lead to miss...BACKGROUND Accurate diagnosis and early resection of colorectal polyps are important to prevent the occurrence of colorectal cancer.However,technical factors and morphological factors of polyps itself can lead to missed diagnoses.Imageenhanced endoscopy and chromoendoscopy(CE)have been developed to facilitate an accurate diagnosis.There have been no reports on visibility using a combination of texture and color enhancement imaging(TXI)and CE for colorectal tumors.AIM To investigate the visibility of margins and surfaces with the combination of TXI and CE for colorectal lesions.METHODS This retrospective study included patients who underwent lower gastrointestinal endoscopy at the Toyoshima Endoscopy Clinic.We extracted polyps that were resected and diagnosed as adenomas or serrated polyps(hyperplastic polyps and sessile serrated lesions)from our endoscopic database.An expert endoscopist performed the lower gastrointestinal endoscopies and observed the lesion using white light imaging(WLI),TXI,CE,and TXI+CE modalities.Indigo carmine dye was used for CE.Three expert endoscopists rated the visibility of the margin and surface patterns in four ranks,from 1 to 4.The primary outcomes were the average visibility scores for the margin and surface patterns based on the WLI,TXI,CE,and TXI+CE observations.Visibility scores between the four modalities were compared by the Kruskal-Wallis and Dunn tests.RESULTS A total of 48 patients with 81 polyps were assessed.The histological subtypes included 50 tubular adenomas,16 hyperplastic polyps,and 15 sessile serrated lesions.The visibility scores for the margins based on WLI,TXI,CE,and TXI+CE were 2.44±0.93,2.90±0.93,3.37±0.74,and 3.75±0.49,respectively.The visibility scores for the surface based on WLI,TXI,CE,and TXI+CE were 2.25±0.80,2.84±0.84,3.12±0.72,and 3.51±0.60,respectively.The visibility scores for the detection and surface on TXI were significantly lower than that on CE but higher than that on WLI(P<0.001).The visibility scores for the margin and surface on TXI+CE were significantly higher than those on CE(P<0.001).In the sub-analysis of adenomas,the visibility for the margin and surface on TXI+CE was significantly better than that on WLI,TXI,and CE(P<0.001).In the sub-analysis of serrated polyps,the visibility for the margin and surface on TXI+CE was also significantly better than that on WLI,TXI,and CE(P<0.001).CONCLUSION TXI+CE enhanced the visibility of the margin and surface compared to WLI,TXI,and CE for colorectal lesions.展开更多
Degradation of the Indigo Carmine(IC) by the bipolar pulsed DBD in water-air mixture was studied. Effects of various parameters such as gas flow rate, solution conductivity, pulse repetitive rate and ect., on color re...Degradation of the Indigo Carmine(IC) by the bipolar pulsed DBD in water-air mixture was studied. Effects of various parameters such as gas flow rate, solution conductivity, pulse repetitive rate and ect., on color removal efficiency of dying wastewater were investigated. Concentrations of gas phase O 3 and aqueous phase H 2O 2 under various conditions were measured. Experimental results showed that air bubbling facilitates the breakdown of water and promotes generation of chemically active species. Color removal efficiency of IC solution can be greatly improved by the air aeration under various solution conductivities. Decolorization efficiency increases with the increase of the gas flow rate, and decreases with the increase of the initial solution conductivity. A higher pulse repetitive rate and a larger pulse capacitor C\-p are favorable for the decolorization process. Ozone and hydrogen peroxide formed decreases with the increase of initial solution conductivity. In addition, preliminary analysis of the decolorization mechanisms is given.展开更多
The physicochemical degradation of Indigo Carmine (IC) dye in aqueous solution was performed using single and combined Advanced Oxidation Processes (AOP’s). Photocatalysis (TiO<sub>2</sub>-UV), Ozonation ...The physicochemical degradation of Indigo Carmine (IC) dye in aqueous solution was performed using single and combined Advanced Oxidation Processes (AOP’s). Photocatalysis (TiO<sub>2</sub>-UV), Ozonation (O<sub>3</sub>) and Sonolysis (SN) were tested either in a standalone methodology or by combination of two simultaneous AOP’s. The dye conversion was followed by both measurements: 1) color removal determined by UV-VIS spectrometry and 2) organic and inorganic load determined by the chemical oxygen demand (COD). A complete and quick color disappearance of model water waste has been obtained by using combination of non-irradiated AOP’s, namely, O3</sub>/SN, which contrasts to the combination of irradiated photocatalysis with O3</sub> or sonolysis. Color removal with simultaneous TiO2</sub>-UV/SN reached 77% while TiO2</sub>-UV/O3</sub> reached 96% at similar reaction time. On the other hand, the standalone O3</sub> yielded the highest color removal (94.4%) in 32 minutes whereas SN reached only 39.2% in 4 hours. The standalone light irradiated TiO2</sub>-UV reached 93.3% color re-moval in one hour of reaction time. These results indicated that non-irradiated (SN and O3</sub>) enhance synergistic effects that provoke structural changes in dye molecule without reaching total degradation. This is evidenced from FTIR of residuals from reaction mixture in which it has been observed the presence of organic molecules such as aromatics, sulfonic and amines refractory compounds that are mechanisti-cally possible to be found during IC degradation. Also, toxicity tests (MicroTox<sup>?</sup> Technique) were performed using commercially available bacteria culture before and after IC degradation for each AOP and their combination. Reduction of aqueous dye concentration decreased the level of toxicity of the treated water which is the main target of the AOP’s but the presence of the remaining recalcitrant compounds have also toxic effect.展开更多
In this study, C,N,S-doped ZrO2 and a series of Eu doped C,N,S-ZrO2 photocatalysts were synthesized by a coprecipitation method using thiourea as the source of C, N and S and Eu(NO3)·6H2O as source of Eu. The m...In this study, C,N,S-doped ZrO2 and a series of Eu doped C,N,S-ZrO2 photocatalysts were synthesized by a coprecipitation method using thiourea as the source of C, N and S and Eu(NO3)·6H2O as source of Eu. The materials were characterized by X-ray dif-fraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV-visible diffuse reflectance spectroscopy, scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). Indigo carmine (IC) was chosen as a model for organic pollutants and used to evaluate the photocatalytic performance of the photo-catalysts under simulated solar light. Commercial ZrO2 was used as a reference material. XRD and Raman results indicated the for-mation of both tetragonal and monoclinic phase ZrO2 with particle size ranging from 8–30 nm. Multi-element doping had a great in-fluence on the optical responses manifested as red shift in the absorption edge. The highest photocatalytic activity towards IC was observed for the Eu,C,N,S-doped ZrO2 (0.6 mol.%Eu) sample (k=1.09×10–2 min–1). The commercial ZrO2 showed the lowest photo-degradation activity (k=5.83×10–4 min–1). The results showed that the control of Eu doping in the C,N,S-ZrO2 was very important in reducing electron-hole recombination. The synergistic effect of Eu, C, N, and S in the ZrO2 matrix led to enhanced utilization of simulated solar energy for the degradation of IC through narrowing of bandgaps.展开更多
A post-column reaction chemiluminescence detection method in ion chromatography is described in this paper.The chemiluminescence system was indigo cramine-hydrogen peroxide. The chemiluminescence reaction conditions a...A post-column reaction chemiluminescence detection method in ion chromatography is described in this paper.The chemiluminescence system was indigo cramine-hydrogen peroxide. The chemiluminescence reaction conditions and the separation conditions of Co and Cu in chromatography were presented.The detection limits were 1.0 and 2.0×10-8 g/mL for Co and Cu respectively.展开更多
Colonoscopy is the gold standard for the screening and diagnosis of colorectal cancer,resulting in a decrease in the incidence and mortality of colon cancer.However,it has a 21%rate of missed polyps.Several strategies...Colonoscopy is the gold standard for the screening and diagnosis of colorectal cancer,resulting in a decrease in the incidence and mortality of colon cancer.However,it has a 21%rate of missed polyps.Several strategies have been devised to increase polyp detection rates and improve their characterization and delimi-tation.These include chromoendoscopy(CE),the use of other devices such as Endo cuffs,and major advances in endoscopic equipment[high definition,magnification,narrow band imaging,i-scan,flexible spectral imaging color enhancement,texture and color enhancement imaging(TXI),etc.].In the retrospective study by Hiramatsu et al,they compared white-light imaging with CE,TXI,and CE+TXI to determine which of these strategies allows for better definition and delimitation of polyps.They concluded that employing CE associated with TXI stands out as the most effective method to utilize.It remains to be demonstrated whether these results are extrapolatable to other types of virtual CE.Additionally,further investigation is needed in order to ascertain whether this strategy could lead to a reduction in the recurrence of excised lesions and potentially lower the occurrence of interval cancer.展开更多
A new dual-wavelength dual-indicator catalytic kinetic spectrophotometric method for the determination of trace Ru(III)was studied.This method was based on Ru(III)-catalyzing oxidation of Arsenazo I and indigo carmine...A new dual-wavelength dual-indicator catalytic kinetic spectrophotometric method for the determination of trace Ru(III)was studied.This method was based on Ru(III)-catalyzing oxidation of Arsenazo I and indigo carmine by potassium bromate in sulfuric acid.The absorbances of the catalytic and noncatalytic systems were measured at 510 and610 nm,respectively.Under the optimum conditions,the linear range of determination is 0–0.12 lgáml-1and the detection limit is 1.21 9 10-4lgáml-1.The method was applied for the determination of trace Ru(III)in ore samples with satisfactory results.展开更多
BACKGROUND Minute gastric cancers(MGCs)have a favorable prognosis,but they are too small to be detected by endoscopy,with a maximum diameter≤5 mm.AIM To explore endoscopic detection and diagnostic strategies for MGCs...BACKGROUND Minute gastric cancers(MGCs)have a favorable prognosis,but they are too small to be detected by endoscopy,with a maximum diameter≤5 mm.AIM To explore endoscopic detection and diagnostic strategies for MGCs.METHODS This was a real-world observational study.The endoscopic and clinicopathological parameters of 191 MGCs between January 2015 and December 2022 were retrospectively analyzed.Endoscopic discoverable opportunity and typical neoplastic features were emphatically reviewed.RESULTS All MGCs in our study were of a single pathological type,97.38%(186/191)of which were differentiated-type tumors.White light endoscopy(WLE)detected 84.29%(161/191)of MGCs,and the most common morphology of MGCs found by WLE was protruding.Narrow-band imaging(NBI)secondary observation detected 14.14%(27/191)of MGCs,and the most common morphology of MGCs found by NBI was flat.Another three MGCs were detected by indigo carmine third observation.If a well-demarcated border lesion exhibited a typical neoplastic color,such as yellowish-red or whitish under WLE and brownish under NBI,MGCs should be diagnosed.The proportion with high diagnostic confidence by magnifying endoscopy with NBI(ME-NBI)was significantly higher than the proportion with low diagnostic confidence and the only visible groups(94.19%>56.92%>32.50%,P<0.001).CONCLUSION WLE combined with NBI and indigo carmine are helpful for detection of MGCs.A clear demarcation line combined with a typical neoplastic color using nonmagnifying observation is sufficient for diagnosis of MGCs.MENBI improves the endoscopic diagnostic confidence of MGCs.展开更多
A new method for the preparation of rubber sheet strewn with titanium dioxide particles (TiO2-strewn sheet) is presented. This simple and low cost method is based on the use of TiO2 powder (Degussa P25) being stre...A new method for the preparation of rubber sheet strewn with titanium dioxide particles (TiO2-strewn sheet) is presented. This simple and low cost method is based on the use of TiO2 powder (Degussa P25) being strewn onto the sheet made from rubber latex (60% HA) through a steel sieve. The characteristic of the TiO2-strewn sheet was studied by using scanning electron microscopy/energy dispersive X-ray spectrometer (SEM/EDS) and X-ray diffractometer (XRD) techniques. The photocatalytic activity of TiO2-strewn rubber sheet was evaluated using Indigo Carmine (IC) dye as a model for organic dye pollutant in water. The results showed that the TiO2-strewn sheet could degrade IC dye solution under UV light irradiation. The effects of pH, initial concentration, and the intensity of UV light on the photodegradation were also investigated. Kinetics of the photocatalytic degradation was of the first-order reaction. The used TiO2-strewn sheet can be recovered and reused. The recycling uses did not require any cleaning between successive uses and no decline in the photodegradation efficiency was observed compared with freshly prepared TiO2-strewn sheet.展开更多
A highly active visible light-induced BiVO4 photocatalyst was prepared by a simple co-precipitation method using ammonia solution as a pH adjustor and Triton X-100(TX100) as a structure directing agent.The physical ...A highly active visible light-induced BiVO4 photocatalyst was prepared by a simple co-precipitation method using ammonia solution as a pH adjustor and Triton X-100(TX100) as a structure directing agent.The physical properties of the prepared BiVO4photocatalyst were investigated by several techniques such as X-ray diffractometer(XRD),Brunauer-Emmett-Teller(BET) surface area measurement,scanning electron microscopy(SEM),energy dispersive analysis(EDS),Fourier-transformed infrared spectroscopy(FT-IR),photoluminescence(PL),and UV-Vis diffused reflectance spectroscopy(DRS).XRD results revealed the existence of a monoclinic scheelite structure in both the unmodified and the modified samples.The TX100 played a crucial role to control the cuboid-like shape morphology of BiVO4.The DRS results showed that the as-prepared cuboid BiVO4 possessed enhanced visible light absorption range compared with that of the unmodified BiVO4.The photocatalytic activity was evaluated via indigo carmine(IC) degradation under visible light irradiation.The modified BiVO4 showed higher photocatalytic efficiency than the unmodified BiVO4 and the commercial P25-TiO2 which could be ascribed to the better charge separation efficiency.展开更多
基金Our study was approved by the ethics committee of the Certified Institutional Review Board of the Yoyogi Mental Clinic(certificate number.RKK227).
文摘BACKGROUND Accurate diagnosis and early resection of colorectal polyps are important to prevent the occurrence of colorectal cancer.However,technical factors and morphological factors of polyps itself can lead to missed diagnoses.Imageenhanced endoscopy and chromoendoscopy(CE)have been developed to facilitate an accurate diagnosis.There have been no reports on visibility using a combination of texture and color enhancement imaging(TXI)and CE for colorectal tumors.AIM To investigate the visibility of margins and surfaces with the combination of TXI and CE for colorectal lesions.METHODS This retrospective study included patients who underwent lower gastrointestinal endoscopy at the Toyoshima Endoscopy Clinic.We extracted polyps that were resected and diagnosed as adenomas or serrated polyps(hyperplastic polyps and sessile serrated lesions)from our endoscopic database.An expert endoscopist performed the lower gastrointestinal endoscopies and observed the lesion using white light imaging(WLI),TXI,CE,and TXI+CE modalities.Indigo carmine dye was used for CE.Three expert endoscopists rated the visibility of the margin and surface patterns in four ranks,from 1 to 4.The primary outcomes were the average visibility scores for the margin and surface patterns based on the WLI,TXI,CE,and TXI+CE observations.Visibility scores between the four modalities were compared by the Kruskal-Wallis and Dunn tests.RESULTS A total of 48 patients with 81 polyps were assessed.The histological subtypes included 50 tubular adenomas,16 hyperplastic polyps,and 15 sessile serrated lesions.The visibility scores for the margins based on WLI,TXI,CE,and TXI+CE were 2.44±0.93,2.90±0.93,3.37±0.74,and 3.75±0.49,respectively.The visibility scores for the surface based on WLI,TXI,CE,and TXI+CE were 2.25±0.80,2.84±0.84,3.12±0.72,and 3.51±0.60,respectively.The visibility scores for the detection and surface on TXI were significantly lower than that on CE but higher than that on WLI(P<0.001).The visibility scores for the margin and surface on TXI+CE were significantly higher than those on CE(P<0.001).In the sub-analysis of adenomas,the visibility for the margin and surface on TXI+CE was significantly better than that on WLI,TXI,and CE(P<0.001).In the sub-analysis of serrated polyps,the visibility for the margin and surface on TXI+CE was also significantly better than that on WLI,TXI,and CE(P<0.001).CONCLUSION TXI+CE enhanced the visibility of the margin and surface compared to WLI,TXI,and CE for colorectal lesions.
文摘Degradation of the Indigo Carmine(IC) by the bipolar pulsed DBD in water-air mixture was studied. Effects of various parameters such as gas flow rate, solution conductivity, pulse repetitive rate and ect., on color removal efficiency of dying wastewater were investigated. Concentrations of gas phase O 3 and aqueous phase H 2O 2 under various conditions were measured. Experimental results showed that air bubbling facilitates the breakdown of water and promotes generation of chemically active species. Color removal efficiency of IC solution can be greatly improved by the air aeration under various solution conductivities. Decolorization efficiency increases with the increase of the gas flow rate, and decreases with the increase of the initial solution conductivity. A higher pulse repetitive rate and a larger pulse capacitor C\-p are favorable for the decolorization process. Ozone and hydrogen peroxide formed decreases with the increase of initial solution conductivity. In addition, preliminary analysis of the decolorization mechanisms is given.
文摘The physicochemical degradation of Indigo Carmine (IC) dye in aqueous solution was performed using single and combined Advanced Oxidation Processes (AOP’s). Photocatalysis (TiO<sub>2</sub>-UV), Ozonation (O<sub>3</sub>) and Sonolysis (SN) were tested either in a standalone methodology or by combination of two simultaneous AOP’s. The dye conversion was followed by both measurements: 1) color removal determined by UV-VIS spectrometry and 2) organic and inorganic load determined by the chemical oxygen demand (COD). A complete and quick color disappearance of model water waste has been obtained by using combination of non-irradiated AOP’s, namely, O3</sub>/SN, which contrasts to the combination of irradiated photocatalysis with O3</sub> or sonolysis. Color removal with simultaneous TiO2</sub>-UV/SN reached 77% while TiO2</sub>-UV/O3</sub> reached 96% at similar reaction time. On the other hand, the standalone O3</sub> yielded the highest color removal (94.4%) in 32 minutes whereas SN reached only 39.2% in 4 hours. The standalone light irradiated TiO2</sub>-UV reached 93.3% color re-moval in one hour of reaction time. These results indicated that non-irradiated (SN and O3</sub>) enhance synergistic effects that provoke structural changes in dye molecule without reaching total degradation. This is evidenced from FTIR of residuals from reaction mixture in which it has been observed the presence of organic molecules such as aromatics, sulfonic and amines refractory compounds that are mechanisti-cally possible to be found during IC degradation. Also, toxicity tests (MicroTox<sup>?</sup> Technique) were performed using commercially available bacteria culture before and after IC degradation for each AOP and their combination. Reduction of aqueous dye concentration decreased the level of toxicity of the treated water which is the main target of the AOP’s but the presence of the remaining recalcitrant compounds have also toxic effect.
基金Project supported by the National Research Fund of South Africa
文摘In this study, C,N,S-doped ZrO2 and a series of Eu doped C,N,S-ZrO2 photocatalysts were synthesized by a coprecipitation method using thiourea as the source of C, N and S and Eu(NO3)·6H2O as source of Eu. The materials were characterized by X-ray dif-fraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV-visible diffuse reflectance spectroscopy, scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). Indigo carmine (IC) was chosen as a model for organic pollutants and used to evaluate the photocatalytic performance of the photo-catalysts under simulated solar light. Commercial ZrO2 was used as a reference material. XRD and Raman results indicated the for-mation of both tetragonal and monoclinic phase ZrO2 with particle size ranging from 8–30 nm. Multi-element doping had a great in-fluence on the optical responses manifested as red shift in the absorption edge. The highest photocatalytic activity towards IC was observed for the Eu,C,N,S-doped ZrO2 (0.6 mol.%Eu) sample (k=1.09×10–2 min–1). The commercial ZrO2 showed the lowest photo-degradation activity (k=5.83×10–4 min–1). The results showed that the control of Eu doping in the C,N,S-ZrO2 was very important in reducing electron-hole recombination. The synergistic effect of Eu, C, N, and S in the ZrO2 matrix led to enhanced utilization of simulated solar energy for the degradation of IC through narrowing of bandgaps.
文摘A post-column reaction chemiluminescence detection method in ion chromatography is described in this paper.The chemiluminescence system was indigo cramine-hydrogen peroxide. The chemiluminescence reaction conditions and the separation conditions of Co and Cu in chromatography were presented.The detection limits were 1.0 and 2.0×10-8 g/mL for Co and Cu respectively.
文摘Colonoscopy is the gold standard for the screening and diagnosis of colorectal cancer,resulting in a decrease in the incidence and mortality of colon cancer.However,it has a 21%rate of missed polyps.Several strategies have been devised to increase polyp detection rates and improve their characterization and delimi-tation.These include chromoendoscopy(CE),the use of other devices such as Endo cuffs,and major advances in endoscopic equipment[high definition,magnification,narrow band imaging,i-scan,flexible spectral imaging color enhancement,texture and color enhancement imaging(TXI),etc.].In the retrospective study by Hiramatsu et al,they compared white-light imaging with CE,TXI,and CE+TXI to determine which of these strategies allows for better definition and delimitation of polyps.They concluded that employing CE associated with TXI stands out as the most effective method to utilize.It remains to be demonstrated whether these results are extrapolatable to other types of virtual CE.Additionally,further investigation is needed in order to ascertain whether this strategy could lead to a reduction in the recurrence of excised lesions and potentially lower the occurrence of interval cancer.
基金supported by the National Natural Science Foundation of China (No. 51273172)
文摘A new dual-wavelength dual-indicator catalytic kinetic spectrophotometric method for the determination of trace Ru(III)was studied.This method was based on Ru(III)-catalyzing oxidation of Arsenazo I and indigo carmine by potassium bromate in sulfuric acid.The absorbances of the catalytic and noncatalytic systems were measured at 510 and610 nm,respectively.Under the optimum conditions,the linear range of determination is 0–0.12 lgáml-1and the detection limit is 1.21 9 10-4lgáml-1.The method was applied for the determination of trace Ru(III)in ore samples with satisfactory results.
基金Supported by the National Science Foundation Committee of China,No 81372348and Clinical Research Fund Project of Zhejiang Medical Association,No 2020ZYC-A10.
文摘BACKGROUND Minute gastric cancers(MGCs)have a favorable prognosis,but they are too small to be detected by endoscopy,with a maximum diameter≤5 mm.AIM To explore endoscopic detection and diagnostic strategies for MGCs.METHODS This was a real-world observational study.The endoscopic and clinicopathological parameters of 191 MGCs between January 2015 and December 2022 were retrospectively analyzed.Endoscopic discoverable opportunity and typical neoplastic features were emphatically reviewed.RESULTS All MGCs in our study were of a single pathological type,97.38%(186/191)of which were differentiated-type tumors.White light endoscopy(WLE)detected 84.29%(161/191)of MGCs,and the most common morphology of MGCs found by WLE was protruding.Narrow-band imaging(NBI)secondary observation detected 14.14%(27/191)of MGCs,and the most common morphology of MGCs found by NBI was flat.Another three MGCs were detected by indigo carmine third observation.If a well-demarcated border lesion exhibited a typical neoplastic color,such as yellowish-red or whitish under WLE and brownish under NBI,MGCs should be diagnosed.The proportion with high diagnostic confidence by magnifying endoscopy with NBI(ME-NBI)was significantly higher than the proportion with low diagnostic confidence and the only visible groups(94.19%>56.92%>32.50%,P<0.001).CONCLUSION WLE combined with NBI and indigo carmine are helpful for detection of MGCs.A clear demarcation line combined with a typical neoplastic color using nonmagnifying observation is sufficient for diagnosis of MGCs.MENBI improves the endoscopic diagnostic confidence of MGCs.
基金supported by the Thailand Research Fund through the Royal Golden Jubilee Ph.D. Program(No. PHD/0003/2550),the Graduate School-PSU, and the Center for Innovation in Chemistry (PERCH-CIC),Commission on Higher Education, Ministry of Education
文摘A new method for the preparation of rubber sheet strewn with titanium dioxide particles (TiO2-strewn sheet) is presented. This simple and low cost method is based on the use of TiO2 powder (Degussa P25) being strewn onto the sheet made from rubber latex (60% HA) through a steel sieve. The characteristic of the TiO2-strewn sheet was studied by using scanning electron microscopy/energy dispersive X-ray spectrometer (SEM/EDS) and X-ray diffractometer (XRD) techniques. The photocatalytic activity of TiO2-strewn rubber sheet was evaluated using Indigo Carmine (IC) dye as a model for organic dye pollutant in water. The results showed that the TiO2-strewn sheet could degrade IC dye solution under UV light irradiation. The effects of pH, initial concentration, and the intensity of UV light on the photodegradation were also investigated. Kinetics of the photocatalytic degradation was of the first-order reaction. The used TiO2-strewn sheet can be recovered and reused. The recycling uses did not require any cleaning between successive uses and no decline in the photodegradation efficiency was observed compared with freshly prepared TiO2-strewn sheet.
基金supported by the Faculty of Science,Silpakorn University,Thailand(Grant No.RGP 2555-06)
文摘A highly active visible light-induced BiVO4 photocatalyst was prepared by a simple co-precipitation method using ammonia solution as a pH adjustor and Triton X-100(TX100) as a structure directing agent.The physical properties of the prepared BiVO4photocatalyst were investigated by several techniques such as X-ray diffractometer(XRD),Brunauer-Emmett-Teller(BET) surface area measurement,scanning electron microscopy(SEM),energy dispersive analysis(EDS),Fourier-transformed infrared spectroscopy(FT-IR),photoluminescence(PL),and UV-Vis diffused reflectance spectroscopy(DRS).XRD results revealed the existence of a monoclinic scheelite structure in both the unmodified and the modified samples.The TX100 played a crucial role to control the cuboid-like shape morphology of BiVO4.The DRS results showed that the as-prepared cuboid BiVO4 possessed enhanced visible light absorption range compared with that of the unmodified BiVO4.The photocatalytic activity was evaluated via indigo carmine(IC) degradation under visible light irradiation.The modified BiVO4 showed higher photocatalytic efficiency than the unmodified BiVO4 and the commercial P25-TiO2 which could be ascribed to the better charge separation efficiency.