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Resource utilization of carbon dioxide (CO 2 ) as alternative carbon feedstock is a promising solution to problems of both the energy supply and global warming. Herein, a biomimetic photoelectrocatalytic interface was covalently constructed utilizing cobalt-containing zeolite imidazolate framework (ZIF9) as CO 2 fixation and activation substrate, and Co 3 O 4 nanowires (NWs) as the photoelectrocatalyst. Adsorption experiments demonstrated that CO 2 could be concentrated on ZIF9 modified Co 3 O 4 NWs. The CO 2 surface concentration exhibited a 3.44 fold increment on this hybrid interface than that on Co 3 O 4 NWs. Theoretical calculation elucidated ZIF9 has the capacity for activating CO 2 molecule via binding Co atom to the O atom of CO 2 , resulting in the onset potential of CO 2 reduction 284 mV positively shift on ZIF9-Co 3 O 4 NWs than that on Co 3 O 4 NWs. At a low overpotential of 290 mV, CO 2 has been photoelectrocatalytically conversion to formate with high conversion rate of 72.3 μmol L −1 cm −2 h −1 and high selectivity of nearly 100% in liquid products. And the heterogeneous electron transfer constant was 2.096 × 10 −3 cm s −1 . This CO 2 conversion process was confirmed to be an instantaneous proton-coupled 2-electron transfer process. This work opens the opportunity for constructing biomimetic photoelectrocatalytic interface with CO 2 adsorption, activation and conversion to efficient CO 2 resource utilization. [ABSTRACT FROM AUTHOR]

A visible-light driven photoelectrochemical (PEC) sensor based on aptamer immobilized TiO2-Fe2O3 nanotubes was proposed for the first time and highly sensitive and selective bisphenol A determination was realized. Taking advantage of the alloy oxide nanotube structure, high surface area, good biocompatibility, superior photoelectrocatalytic performance, a limit of detection toward BPA as low as 1.8×10−11 M with linearity in the range from 1.8×10−11 to 3.2×10−9 M could be achieved. Specificity was greatly exhibited for this aptasensor under 100-fold excess concentration of estriol, resorcinol, nonylphenol, 2,4-D, acetamiprid, chlorpyrifos and omethoate. Simultaneously, satisfactory results were obtained in real water sample investigation from industrial plastics and drinking water. A novel visible-light driven PEC method for highly sensitive and selective detection of BPA was thus established. [ABSTRACT FROM AUTHOR]

Photo/electrochemical CO 2 reduction using pyridine was feasible to produce methanol via the formation of pyridiniumformate intermediate. To improve the reduction efficiency, a pyridyl bonded ruthenium (II)-based photosensitizer catalyst (Ru-Py) was designed for photoelectrochemical CO 2 conversion. The photocurrent density on Ru-Py modified electrode in CO 2 saturated solution was 0.103 mA cm −2 higher than that without illumination. The total Faradaic efficiency (f) reached 83.1%, whereas the turnover number (TON) for methanol was 38.4 in aqueous solution after 8 h irradiation. The methanol production was 24.1 μmol which was higher than the published literatures (less than 8 μmol) in similar systems could be attributed to the efficient electron transfer between the photosensitizer and the pyridyl active site covalently linked by C-C bond, as well as the strong and wide absorption up to 610 nm resulted from the large conjugated structure of the ligands. The mechanism investigation revealed that the N atom in pyridyl as catalytic active sites played significant role in CO 2 conversion by forming the pyridiniumformate intermediate which was confirmed by the simulation reaction. Meanwhile, in order to realize the reduction process intuitively, the density functional theory (DFT) was applied to simulate the structure of Ru-Py and the pyridiniumformate intermediates. [ABSTRACT FROM AUTHOR]

Abstract: To solve the problem of poor selectivity on photoelectrochemical (PEC) oxidation toward small organic molecules especially has the similar chemical structures, a novel method in this work was proposed for achieving a high selective PEC oxidation by constructing molecularly imprinted sites on a single crystalline (SC) ZnO surface (imp-ZnO). Though a crystal-seed-assisted hydrothermal method, the phenol (C6H5-OH) imp-ZnO and p-hydroxybenzoic acid (PHBA, HOOC-C6H4-OH) imp-ZnO electrodes were prepared, which were in the form of vertically aligned nanorods with maintained single crystalline. The results showed the high selective PEC oxidation capabilities were obtained on SC imp-ZnO electrodes toward target between phenol and PHBA, with selective factor R of 5.64 and 2.38 respectively. This was attributed to their excellent imprinted expression with high value of imprinting factor S (1.86 and 1.55), deriving from an obvious difference of photocurrent enhancement (5.5–8 times) on SC imp-ZnO between target and nontarget. Such kind of single crystalline ZnO substrate is essential to constructed high-quality molecularly imprinted sites with clear size and hard shape for a great recognition effect. [Copyright &y& Elsevier]

Abstract: Highly selective and sensitive determination of profenofos (PFF) is achieved by fast and convenient visible-light-driven photoelectrochemical (PEC) sensor with a low detection limit of 1nM (S/N=3). The sensor is fabricated on highly ordered and vertically aligned TiO2 nanotubes (NTs) employing p-tert-butylcalix[4]arene (CA) as recognition element and visible-light sensitizer. It shows excellent selectivity towards PFF, and 100-fold excess of coexistent interferences only causes minor changes of the photocurrent of PFF. Mechanism study suggests that this high selectivity may be attributed to the specific binding ability of CA to PFF, and it is further confirmed by molecular docking calculations. The best binding mode between CA and PFF is also proposed. [Copyright &y& Elsevier]