Heterophase Photocatalysts from Water-Soluble Conjugated Polyelectrolytes: An Example of Self-Initiation under Visible Light

Highly crystalline titania nano-particles were synthesized by hydrothermal method using novel stable water-soluble titanium complexes. It was confirmed that single phase anatase, rutile and brookite, which can be rarely synthesized as a single phase, can be obtained by varying the ligand in the complex and pH of the aqueous solution. TEM observations and BET specific surface area measurements had shown that these samples consisted of nanosized particles of 5~200 nm and had high specific surface areas of 25~150 m2/g. According to UV-visible diffuse reflectance spectra, these titania samples absorbed light in the visible region (λ > 400 nm). Photocatalytic activities in NO oxidation reaction exhibited by synthesized titania powders under the irradiation by UV- visible light were higher than the activity of the commercial TiO2 photocatalyst P25 (Degussa). Especially, under illumination by only visible light of above 510 nm wavelength, photocatalytic activity of the obtained specimens exceeded that of P25 more than four times. We also clearly demonstrated that single phase brookite had high photocatalytic activity for NO oxidation.

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Water‐soluble Organic Photocatalyst Discovered for Highly Efficient Additive‐Free Visible‐Light‐Driven Grafting of Polymers from a Protein at Ambient and Aqueous Environments

Advanced Materials ◽

10.1002/adma.202108446 ◽

2022 ◽

pp. 2108446

Author(s):

Yungyeong Lee ◽

Yonghwan Kwon ◽

Youngmu Kim ◽

Changhoon Yu ◽

Siyang Feng ◽

...

Keyword(s):

Visible Light ◽

Water Soluble ◽

Highly Efficient ◽

Aqueous Environments ◽

Visible Light Driven

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Visible photostability of some ruthenium and platinum phthalocyanines in water and in the presence of organic substrates

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424610002306 ◽

2010 ◽

Vol 14 (06) ◽

pp. 499-508 ◽

Cited By ~ 5

Author(s):

Manuela Carchesio ◽

Lucia Tonucci ◽

Nicola d'Alessandro ◽

Antonino Morvillo ◽

Piero Del Boccio ◽

...

Keyword(s):

Visible Light ◽

Visible Light Irradiation ◽

Carbonyl Compounds ◽

Furfuryl Alcohol ◽

Phenylacetic Acid ◽

Water Soluble ◽

Light Irradiation ◽

Organic Substrates ◽

Visible Spectra ◽

Trapping Agent

Water-soluble, metal-tetrasubstituted phthalocyanines ( -SO3H , MPcS and -COOH , MPcC) of platinum and ruthenium were synthesized and their photostability to visible light irradiation was determined. For the ruthenium phthalocyanines, the characteristic visible Q band of the phthalocyanines was almost totally suppressed after five days of irradiation. The platinum derivatives were instead more resistant to photodegradation, and the Q band did not decrease by more than 25%. The addition of carbonyl compounds to the phthalocyanine solution in water (at concentrations at least 1400-fold those of the phthalocyanines) dramatically accelerated the photobleaching of these phthalocyanine complexes. PtPcS turned from blue to green and to colorless with one day of visible-light irradiation in the presence of acetone. This effect decreased with the increase in molecular weight of the ketones (from acetone to 2-pentanone). The addition of alcohols (i.e. 1-butanol) or other organics (i.e. phenylacetic acid) did not affect the photostability of these metal-tetrasubstituted phthalocyanines. Dioxygen also had an important role, as when the solutions of phthalocyanines were carefully deaerated before irradiation, the visible spectra were preserved. The platinum phthalocyanines, as with the palladium analogs, sensitize the photoproduction of 1O2 , as shown by the formation of endoperoxide and its rearranged products in the presence of furfuryl alcohol (a singlet oxygen trapping agent).

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