Recent Advances in Electrochemical, Photochemical, and Photoelectrochemical Reduction of CO2 to C2+ Products.

Environmental problems such as global warming are one of the most prominent global challenges. Researchers are investigating various methods for decreasing CO2 emissions. The CO2 reduction reaction via electrochemical, photochemical, and photoelectrochemical processes has been a popular research topic because the energy it requires can be sourced from renewable sources. The CO2 reduction reaction converts stable CO2 molecules into useful products such as CO, CH4 , C2 H4 , and C2 H5 OH. To obtain economic benefits from these products, it is important to convert them into hydrocarbons above C2 . Numerous investigations have demonstrated the uniqueness of the CC coupling reaction of Cu-based catalysts for the conversion of CO2 into useful hydrocarbons above C2 for electrocatalysis. Herein, the principle of semiconductors for photocatalysis is briefly introduced, followed by a description of the obstacles for C2+ production. This review presents an overview of the mechanism of hydrocarbon formation above C2 , along with advances in the improvement, direction, and comprehension of the CO2 reduction reaction via electrochemical, photochemical, and photoelectrochemical processes.

Modulation of theta phase synchronization in the human electroencephalogram during a recognition memory task.

To the extent that recognition memory relies on interactions among widely distributed neural assemblies across the brain, phase synchronization between brain rhythms may play an important role in meditating those interactions. As the theta rhythm is known to modulate in power during the recognition memory process, we aimed to determine how the phase synchronization of the theta rhythms across the brain changes with recognition memory. Fourteen human participants performed a visual object recognition task in a virtual reality environment. Electroencephalograms were recorded from the scalp of the participants while they either recognized objects that had been presented previously or identified new objects. From the electroencephalogram recordings, we analyzed the phase-locking value of the theta rhythms, which indicates the degree of phase synchronization. We found that the overall phase-locking value recorded during the recognition of previously viewed objects was greater than that recorded during the identification of new objects. Specifically, the theta rhythms became strongly synchronized between the frontal and the left parietal areas during the recognition of previously viewed objects. These results suggest that the recognition memory process may involve an interaction between the frontal and the left parietal cortical regions mediated by theta phase synchronization.