Dye functionalized carbon nanotubes for photoelectrochemical water splitting – role of inner tubes

Abstract

Dye functionalized double- and triple-walled carbon nanotubes are effective photoanodes for water splitting without the attachment of semiconductor and water oxidation catalysts.

Effect of Carbon Nanotubes on Direct Electron Transfer and Electrocatalytic Activity of Immobilized Glucose Oxidase

“…The promotion effect of inner tubes has also been demonstrated most recently on the dye-functionalized CNTs for PEC water splitting, in which the dye-functionalized DWNTs and TWNTs show a much higher PEC activity for water splitting as compared to that of SWNTs and MWNTs. 35 In other words, the promotion effect of CNTs via the electron-tunneling mechanism is an intrinsic property of CNTs with a defined number of walls. Thus, the reason for the observation of the highest DET and electrocatalytic activity of GO X immobilized on CNT-2, a mixture of TWNTs and DWNTs, is most likely the facile charge-transfer process via the electron tunneling between the outer wall and inner tubes of CNT-2 under the influence of an electrochemical driving force, which is consistent with previous studies.…”

“…Similar volcano curves were also observed on Pt and Pd NP-supported CNTs for methanol, ethylene glycol, ethanol, and formic acid oxidation in alkaline solutions and on dye-functionalized CNTs for photoelectrochemical (PEC) water splitting. 32 − 35 This indicates that the number of walls or inner tubes of CNTs plays an important role in promoting the ET of the electrochemical redox reaction on the surface of CNTs, and such a promotion effect could be beneficial to the DET of the redox reactions of enzymes/proteins. Here, the effects of quantum properties of CNTs on the DET and electrocatalytic activity of GO X toward glucose oxidation were studied.…”

Intrinsic Effect of Carbon Supports on the Activity and Stability of Precious Metal Based Catalysts for Electrocatalytic Alcohol Oxidation in Fuel Cells: A Review

“…Most significantly, the distinctive volcano‐type dependence of the activity of Pd–CNTs for AORs on the number of CNT walls is similar to the electrocatalytic activity of pristine CNTs for ORR, the O 2 evolution reaction (OER), and the H 2 evolution reaction (HER), dye‐functionalized CNTs for photoelectrochemical water splitting, and CNT‐immobilized glucose oxidase . The electrocatalytic activity of double‐walled CNTs (DWCNTs) and TWCNTs is significantly higher than that of SWCNTs and MWCNTs.…”

Iron and Cobalt Corroles in Solution and on Carbon Nanotubes as Molecular Photocatalysts for Hydrogen Production by Water Reduction

“…Nanomaterial composites and structures, including inorganic, molecular, and hybrid organic/inorganic materials, have been explored to meet specific requirements such as a light‐absorbing wavelength modification, photoinduced charge separation, and a faster water‐splitting reaction . Many catalyst systems for energy storage and conversion have been based on carbon nanotubes (CNTs) because they have the capability to contribute, not only in charge injection and extraction, but also in increasing the direct flow of photogenerated electrons . Recently, CNTs were used in the synthesis of different nanomaterials to improve the reduction of oxygen, reduction of nitric oxide, and oxidation of water …”

“…[25] Many catalysts ystems for energy storagea nd conversion have been based on carbon nanotubes (CNTs) because they have the capabilityt oc ontribute, not only in chargei njection and extraction, but also in increasing the directf low of photogenerated electrons. [26][27][28] Recently,C NTsw ere used in the synthesis of differentn anomaterials to improvet he reductiono f oxygen, [27,29,30] reduction of nitric oxide, [30] and oxidation of water. [19,31] In this work, we describe photocatalytic H 2 evolution experiments performed by using cobalta nd iron corroles ( Figure 1A) and discusst he relationship between the catalyste fficiencies and the electrochemical and physicochemicalp roperties.…”