A substantially improved methanol yield was achieved from the photoreduction of carbon dioxide under visible light by using a hybrid photocatalyst consisting of molecular cobalt phthalocyanine tetracarboxylic acid (CoPc-COOH) complex immobilized to the organic semiconductor graphitic carbon nitride (g-C3N4) and triethylamine as sacrificial electron donor. The structural and morphological features of the hybrid photocatalyst determined by various techniques like FTIR, UV–Vis, Raman, XPS, TGA, BET etc. After 24 h of light irradiation, the methanol yield by using g-C3N4/CoPc-COOH photocatalyst (50 mg) was found to be 646.5 µmol g−1cat or 12.9 mmol g−1cat with conversion rate 538.75 µmol h−1 g−1cat. However, the use of homogeneous CoPc-COOH (6.5 µmol Co, equivalent to g-C3N4/CoPc-COOH) and g-C3N4 (50 mg) provided 88.5 μmol (1770 μmol g−1cat) and 59.2 μmol (1184 μmol g−1cat) yield of methanol, respectively under identical conditions. The improved photocatalytic efficiency of the hybrid was attributed to the binding ability of CoPc-COOH to CO2 that provided the higher CO2 concentration on the support. Further, the semiconductor support provided better electron mobility and charge separation with the integrated benefit of facile recovery and recycling of the material at the end of the reduction process.

Highly improved photoreduction of carbon dioxide to methanol using cobalt phthalocyanine grafted to graphitic carbon nitride as photocatalyst under visible light irradiation

Carbon dots (C dots, size < 10 nm) have been conventionally decorated onto semiconductor matrixes for photocatalytic H2 evolution, but the efficiency is largely limited by the low loading ratio of the C dots on the photocatalyst. Here, we propose an inverse structure of Cd0.5Zn0.5S quantum dots (QDs) loaded onto the onionlike carbon (OLC) matrix for noble metal-free photocatalytic H2 evolution. Cd0.5Zn0.5S QDs (6.9 nm) were uniformly distributed on an OLC (30 nm) matrix with both upconverted and downconverted photoluminescence property. Such an inverse structure allows the full optimization of the QD/OLC interfaces for effective energy transfer and charge separation, both of which contribute to efficient H2 generation. An optimized H2 generation rate of 2018 μmol/h/g (under the irradiation of visible light) and 58.6 μmol/h/g (under the irradiation of 550–900 nm light) was achieved in the Cd0.5Zn0.5S/OLC composite samples. The present work shows that using the OLC matrix in such a reverse construction is a...

Loading Cd0.5Zn0.5S Quantum Dots onto Onion-Like Carbon Nanoparticles to Boost Photocatalytic Hydrogen Generation.

In order to realize the photocatalytic reactions by visible light more efficiently, the photocatalytic activity of polycrystalline TiO2 samples impregnated with carboxy functionalized Co(II) or Zn(II)-phthalocyanine as heteregoneous photocatalyst has been investigated. For this purpose, metallophthalocyanines(MPc) substituted with mercapto benzoic acid groups on each benzo moiety were incorporated into TiO2 semiconductors to prepare TiO2–MPc composites as heterogeneous catalysts. TiO2 and TiO2–MPc composites were characterized by making use of X-ray diffraction (XRD), infrared spectroscopy (FTIR) and UV–vis diffuse reflectance spectroscopy. The characterization results show that MPcs are anchored on the surface of TiO2 through CO–O–TiO2 bonds. The optimum loading of the dyes on TiO2 were 0.49 μmol/g TiO2 for ZnPc and 0.56 μmol/g TiO2 for CoPc, nearly independent of TiO2 used. These novel heterogeneous photocatalysts were used for the degradation of 4-chlorophenol (4-CP) in aqueous media in the presence of visible irradiation monitored by GC–MS spectroscopy. The catalysts revealed enhanced activity in visible region for the degradation of 4-CP when compared with that of pure TiO2, which is attributed to the cooperative function of the two components of the photocatalyst. The amount of remaining 4-chlorophenol residue was determined by using an internal standard (phenol) with gas chromatography–mass spectrometry and during the first 30 minutes 99% degradation of 4-chlorophenol was observed.

Photocatalytic degradation of 4-chlorophenol under visible light by using TiO2 catalysts impregnated with Co(II) and Zn(II) phthalocyanine derivatives

An unsymmetrical zinc phthalocyanine with ferrocenylcarborane linked to the phthalocyanine ring through a phenylethynyl spacer was designed for organic field-effect transistor (OFET). The unsymmetrical phthalocyanine derivatives were characterized using a wide range of spectroscopic and electrochemical methods. In particular, the ferrocenylcarborane structure was unambiguously revealed based on the single-crystal X-ray diffraction analysis. In-depth investigations of the electrochemical properties demonstrated that the ferrocenylcarborane insertion extended the electrochemical character of ferrocenylcarborane-substituted phthalocyanine (7). Moreover, in the anodic potential scans, the oxidative electropolymerization of etynylphthalocyanine (6) and 7 was recorded. To clarify the effect of the insertion of ferrocenylcarborane (2) on the field-effect mobility, solution-processed films of 2, 6, and 7 were used as an active layer to fabricate the bottom-gate top-contact OFET devices. An analysis of the output ...

o-Carborane, Ferrocene, and Phthalocyanine Triad for High-Mobility Organic Field-Effect Transistors

Electrochemical polymerization of EDOT modified Phthalocyanines and their applications as electrochromic materials with green coloration, and strong absorption in the Near-IR

Synthesis, electrochemical and spectroelectrochemical properties of novel phthalocyanine complexes of manganese, titanium and indium

Photocatalytic–electrocatalytic dual hydrogen production system

http://jes.ecsdl.org/content/162/3/H170.full.pdf

Electropolymerization of Octakis Diethlyamino Substituted Metallophthalocyanines and Their Electrochromic Characterization

Bu calismada, yeni peripheral 1,2,4-triazol substitue metalsiz 4 , Zn(II) 5 , Ti(IV) 6, Ni(II) 7 ve Co(II) 8 ftalosiyanin turevlerinin sentezi, elektrokimyasal ve spektroelektrokimyasal ozellikleri rapor edilmistir. Komplekslerin voltametrik ve in situ spektroelektrokimyasal karakterizasyonu cozelti icinde gerceklestirildi. Nikel ve cinko ftalosiyaninler karakteristik olarak ortak “enerji araligi”,” pikten pike potansiyel ayrimlar” ve “yarim dalga pik potansiyel degerleri” ile ftalosiyanin halka bazli elektron transfer reaksiyonu verirken, kobalt ve titanyum ftalosiyanin komplekslerinin kavitesinde bulunan Co II ve Ti IV O metal iyonlari redoks aktif katyon olarak davranmistir. Kobalt ftalosiyanin indirgenme reaksiyonunda bir elektron [Co II Pc -2 ]/ [Co I Pc -2 ] -1 verirken, titanyum ftalosiyanin Pc ligand indirgenme islemine ek olarak, iki tane metal bazli indirgenme reaksiyonu [Ti IV OPc -2 ]/[Ti III OPc -2 ] -1 ve [Ti III OPc -2 ] -1 /[Ti III OPc -2 ] -2 gostermistir. Elektron transfer reaksiyonlari komplekslerin spektrumlarini oldukca degistirmistir. Bu durum komplekslerin ozellikle goruntuleme teknolojisinde pratik uygulamalarda en onemli beklentidir. Kobalt ve titanyum komplekslerinin redoks ve spektral yanitlari elektrolitte var olan molekuler oksijen tarafindan etkilenmistir. Bu da komplekslerin molekuler oksijene karsi elektrokatalitik ve elektosensor aktivitesini gostermektedir.

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Mehmet Aydemir

Papers

Synthesis, electrochemical and spectroelectrochemical properties of novel phthalocyanine complexes of manganese, titanium and indium

Photocatalytic–electrocatalytic dual hydrogen production system

Electropolymerization of Octakis Diethlyamino Substituted Metallophthalocyanines and Their Electrochromic Characterization

Peripherally tetra 1,2,4-triazol substituted novel phthalocyanines: Synthesis, characterization, electrochemical and spectroelectrochemical properties