Visible Light–Driven Hydrogen Production by Carbon based Polymeric Materials

Converting solar energy into storable solar fuels such as H2 from earth abundant source—water—is a nice approach to find the solution of energy crisis and environmental protection. There are two half reactions; first, water oxidation into oxygen and proton and followed by proton reduction led to H2 evolution from water. After two decades of continuous attempts, there have been several efficient water oxidation photocatalysts introduced, whereas the proton reduction photocatalyst were relatively less explored. Major portion of reported photocatalysts for proton reduction are mainly derived from either noble metals or precious metals. Carbon-based organic photocatalysts have become attractive recently. These organic materials have several advantages like light weight, cheap, well-defined structure-property relationship and the most attractive one is better batch to batch reproducibility. Here, the reported organic photocatalysts and their performance are summarized which in fact help others to get an idea about ongoing progress in this area of research and to understand the basic designing principle for efficient photocatalysts for fuel production

Electrochemical CO₂ Reduction to CO Catalyzed by 2D Nanostructures

Electrochemical CO₂ reduction towards value-added chemical feedstocks has been extensively studied in recent years to resolve the energy and environmental problems. The practical application of electrochemical CO₂ reduction technology requires a cost-effective, highly efficient, and robust catalyst. To date, vigorous research have been carried out to increase the proficiency of electrocatalysts. In recent years, two-dimensional (2D) graphene and transition metal chalcogenides (TMCs) have displayed excellent activity towards CO₂ reduction. This review focuses on the recent progress of 2D graphene and TMCs for selective electrochemical CO₂ reduction into CO

Electrochemical CO₂ Reduction to CO Catalyzed by 2D Nanostructures

Electrochemical CO₂ reduction towards value-added chemical feedstocks has been extensively studied in recent years to resolve the energy and environmental problems. The practical application of electrochemical CO₂ reduction technology requires a cost-effective, highly efficient, and robust catalyst. To date, vigorous research have been carried out to increase the proficiency of electrocatalysts. In recent years, two-dimensional (2D) graphene and transition metal chalcogenides (TMCs) have displayed excellent activity towards CO₂ reduction. This review focuses on the recent progress of 2D graphene and TMCs for selective electrochemical CO₂ reduction into CO

Recent Advances in Quantum Dots for Photocatalytic CO2 Reduction: A Mini-Review

Solar energy–driven carbon dioxide (CO2) reduction to valuable solar fuels/chemicals (e.g., methane, ethanol, and carbon monoxide) using particulate photocatalysts is regarded as one of the promising and effective approaches to deal with energy scarcity and global warming. The growth of nanotechnology plays an eminent role in improving CO2 reduction (CO2R) efficiencies by means of offering opportunities to tailor the morphology of photocatalysts at a nanoscale regime to achieve enhanced surface reactivity, solar light absorption, and charge separation, which are decisive factors for high CO2R efficiency. Notably, quantum dots (QDs), tiny pieces of semiconductors with sizes below 20 nm, offering a myriad of advantages including maximum surface atoms, very short charge migration lengths, size-dependent energy band positions, multiple exciton generation effect, and unique optical properties, have recently become a rising star in the CO2R application. In this review, we briefly summarized the progress so far achieved in QD-assisted CO2 photoreduction, highlighting the advantages of QDs prepared with diverse chemical compositions such as metal oxides, metal chalcogenides, carbon, metal halide perovskites, and MXenes. © Copyright © 2021 Park, Murali, Modigunta, In and In.1

Sustained, Photocatalytic CO₂ Reduction to CH₄ in a Continuous Flow Reactor by Earth-Abundant Materials: Reduced Titania-Cu₂O Z-Scheme Heterostructures

Photocatalytic conversion of CO₂ and water vapor to hydrocarbon fuels is a promising approach for storing solar energy while reducing greenhouse gas emissions. However, still certain issues including low product yields, limited photocatalyst stability and relatively high cost have hampered practical implementation of this technology. In the present work, a unique strategy is adopted to synthesize a stable, and inexpensive photocatalyst comprised of earth-abundant materials: a reduced titania-Cu₂O Z-scheme heterostructure. Under illumination for 6 h, the optimized reduced titania-Cu₂O photocatalyst enables 0.13 % photoreduction of highly diluted CO₂ with water vapors to 462nmol g⁻¹ of CH₄ while showing excellent stability over seven testing cycles (42 h). Our studies show the Z-scheme inhibits Cu₂O photocorrosion, while its synergistic effects with reduced titania result in sustained CH₄ formation in a continuous flow photoreactor. To the best of our knowledge stability exhibited by the reduced titania-Cu₂O Z-scheme is the highest for any Cu-based photocatalyst

Electrochemical CO2 Reduction to CO Catalyzed by 2D Nanostructures

Electrochemical CO2 reduction towards value-added chemical feedstocks has been extensively studied in recent years to resolve the energy and environmental problems. The practical application of electrochemical CO2 reduction technology requires a cost-effective, highly efficient, and robust catalyst. To date, vigorous research have been carried out to increase the proficiency of electrocatalysts. In recent years, two-dimensional (2D) graphene and transition metal chalcogenides (TMCs) have displayed excellent activity towards CO2 reduction. This review focuses on the recent progress of 2D graphene and TMCs for selective electrochemical CO2 reduction into CO. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.1

Novel Porous Brain Electrodes for Augmented Local Field Potential Signal Detection

Intracerebral local field potential (LFP) measurements are commonly used to monitor brain activity, providing insight into the flow of information across neural networks. Herein we describe synthesis and application of a neural electrode possessing a nano/micro-scale porous surface topology for improved LFP measurement. Compared with conventional brain electrodes, the porous electrodes demonstrate higher measured amplitudes with lower noise levels. © 2019 by the authors.1

Hierarchical Micro/Nano-Porous Acupuncture Needles Offering Enhanced Therapeutic Properties

Acupuncture as a therapeutic intervention has been widely used for treatment of many pathophysiological disorders. For achieving improved therapeutic effects, relatively thick acupuncture needles have been frequently used in clinical practice with, in turn, enhanced stimulation intensity. However due to the discomforting nature of the larger-diameter acupuncture needles there is considerable interest in developing advanced acupuncture therapeutical techniques that provide more comfort with improved efficacy. So motivated, we have developed a new class of acupuncture needles, porous acupuncture needles (PANs) with hierarchical micro/nano-scale conical pores upon the surface, fabricated via a simple and well known electrochemical process, with surface area approximately 20 times greater than conventional acupuncture needles. The performance of these high-surface-area PANs is evaluated by monitoring the electrophysiological and behavioral responses from the in vivo stimulation of Shenmen (HT7) points in Wistar rats, showing PANs to be more effective in controlling electrophysiological and behavioral responses than conventional acupuncture needles. Comparative analysis of cocaine induced locomotor activity using PANs and thick acupuncture needles shows enhanced performance of PANs with significantly less pain sensation. Our work offers a unique pathway for achieving a comfortable and improved acupuncture therapeutic effect. © The Author(s) 2016.1