Photoelectrochemical (PEC) hydrogen production is an emerging technology that uses renewable solar light aimed to establish a sustainable carbon‐neutral society. The barriers to commercialization are ...low efficiency and high cost. To date, researchers have focused on materials and systems. However, recent studies have been conducted to utilize thermal effects in PEC hydrogen production. This Review provides a fresh perspective to utilize the thermal effects for PEC performance enhancement while delineating the underlying principles and equations associated with efficiency. The fundamentals of the thermal effect on the PEC system are summarized from various perspectives: kinetics, thermodynamics, and empirical equations. Based on this, materials are classified as plasmonic metals, quantum dot‐based semiconductors, and photothermal organic materials, which have an inherent response to photothermal irradiation. Finally, the economic viability and challenges of these strategies for PEC are explained, which can pave the way for the future progress in the field.
Thermal effects on PEC: Utilization of heat on photoelectrochemical (PEC) hydrogen evolution reaction (HER) is a promising strategy to increase PEC performance by accelerating charge carrier transport and decreasing applied bias. This Review summarizes the basic principles of thermal effects for PEC HER and introduces materials that enhance these thermal effects, as well as the remaining challenges and future developments.
Solar‐driven photoelectrochemical (PEC) hydrogen production is one potential pathway to establish a carbon‐neutral society. Nowadays, quantum dots (QDs)‐sensitized semiconductors have emerged as ...promising materials for PEC hydrogen production due to their tunable bandgap by size or morphology control, displaying excellent optical and electrical properties. Nevertheless, they still suffer from anodic corrosion during long‐term cycling, offering poor stability. This Review discussed advancements to improve long‐term stability of QDs particularly in terms of cocatalysts and passivation layers. The working principle of PEC cells was reviewed, along with all important configurations adopted over recent years. The equations to assess PEC performance were also described. A greater emphasized was placed on QDs and incorporation of cocatalysts or passivation layers that could enhance the PEC performance by influencing the charge transfer and surface recombination processes.
Photoelectrochemical hydrogen evolution: Quantum dots (QDs)‐based semiconductor is an emerging material for photoelectrochemical (PEC) hydrogen generation. Recently, researchers have studied QDs‐based semiconductors with cocatalyst and passivation layer to improve the efficiency and durability. This Review provides their uses and basic principles for PEC hydrogen evolution.
Poly (lactic acid) (PLA) is an important biodegradable plastic with unique properties. However, its widespread application is hindered by its low miscibility and suboptimal degradation properties. To ...overcome these limitations, we investigated the mechanical, thermal, and degradation properties of PLA and poly (butylene sebacate‐co‐terephthalate) (PBSeT) blends in the presence of poly (ethylene oxide) (PEO). Specifically, this study aimed to identify the effects of PEO as a compatibilizer and hydrolysis accelerator in PLA/PBSeT blends. PLA (80%) and PBSeT (20%) were melt blended with various PEO contents (2–10 phr), and their mechanical, thermal, and hydrolytic properties were analyzed. All PEO‐treated blends exhibited a higher elongation at break than that of the control sample, and the tensile strength was slightly reduced. In the PEO 10% sample, the elongation at break increased to 800% of that of the control sample. Differential scanning chromatography (DSC) analysis confirmed that when PEO was added to the PLA/PBSeT blends, the two glass transition temperatures (Tg) narrowed, resulting in improved miscibility of PLA and PBSeT. In addition, the hydrolytic degradation of the PLA/PBSeT/PEO blend accelerated as the PEO content increased. It was confirmed that PEO can act as a compatibilizer and hydrolysis‐accelerating agent for PLA/PBSeT blends.
In principle, photocatalytic activity can be precisely controlled with crystalline catalysts. However, an amorphous photocatalyst could be a viable candidate for CO2 photoreduction to form ...value‐added products. The amorphous phase is currently part of the crystalline material in several ongoing CO2 photoreduction studies. Additionally, no study indicates the amorphous material required for overall CO2 photoreduction. This perspective review article highlights fundamental assumptions that are necessary to gain insights and understand the effectiveness of amorphous photocatalysts for CO2 photoreduction. We start with basic ideas and theories about these materials, including light harvesting, variable coordination number, and the interaction of CO2 molecules with the amorphous catalytic surface. To understand the prospects of the amorphous photocatalyst, we explore machine learning with EXAFS. Furthermore, we discuss product selectivity and regeneration of photocatalysts in detail. Finally, we briefly review the work in progress on amorphous materials and compare it to that on crystalline ones.
Helping amorphous photocatalysts to take shape: Although developing an amorphous photocatalyst for CO2 photoreduction may be challenging, it can perform better than crystalline photocatalysts if specific properties are considered. These include light harvesting, charge kinetics, short‐range active sites, and reaction mechanisms. EXAFS and machine learning could be powerful tools for gaining insights into amorphous photocatalysts.
In this study, poly(butylene adipate‐co‐terephthalate) (PBAT) biocomposites were generated from spent coffee grounds (SCGs) or torrefied SCG (TSCGs) using a melt compounding process. TSCGs were ...obtained at torrefaction temperatures of 230, 245, 260, 275, or 290°C for a duration of 60 min. Torrefaction enhanced the hydrophobicity, grindability, and biomass stability of the resulting composites by eliminating hemicellulose. Various concentrations of SCGs (10 and 20 wt.%) and TSCGs (10, 20, and 30 wt.%) were compounded into PBAT. The thermal, mechanical, and degradation properties of PBAT biocomposites were investigated. As SCGs and TSCGs were introduced, the crystallization temperature drastically increased. Compared with PBAT biocomposites with SCGs, PBAT biocomposites with TSCGs exhibited higher thermal stability and hydrophobicity, and improved mechanical properties. Further, alkaline hydrolysis occurred at a faster rate for biocomposites with biofillers than for neat PBAT. Therefore, this study demonstrated the improved compatibility between SCGs and PBAT by torrefaction.
Schematic diagram from film processing to analysis.
Heavy‐metal‐free ternary Cu–In–Se quantum dots (CISe QDs) are promising for solar fuel production because of their low toxicity, tunable band gap, and high light absorption coefficient. Although ...defects significantly affect the photophysical properties of QDs, the influence on photoelectrochemical hydrogen production is not well understood. Herein, we present the defect engineering of CISe QDs for efficient solar‐energy conversion. Lewis acid–base reactions between metal halide–oleylamine complexes and oleylammonium selenocarbamate are modulated to achieve CISe QDs with the controlled amount of Cu vacancies without changing their morphology. Among them, CISe QDs with In/Cu = 1.55 show the most outstanding photoelectrochemical hydrogen generation with excellent photocurrent density of up to 10.7 mA cm−2 (at 0.6 VRHE), attributed to the suitable electronic band structures and enhanced carrier concentrations/lifetimes of the QDs. The proposed method, which can effectively control the defects in heavy‐metal‐free ternary QDs, offers a deeper understanding of the effects of the defects and provides a practical approach to enhance photoelectrochemical hydrogen generation.
Defect engineering of ternary Cu–In–Se quantum dots is achieved by regulating Lewis acid–base reactions between metal halide–oleylamine complexes and selenium precursors. Optical and electrical properties such as carrier concentrations, mobilities, and lifetimes are tuneable by the density of Cu vacancies. Photoanodes with defect‐engineered quantum dots show outstanding photoelectrochemical hydrogen generation with excellent photocurrent density (10.7 mA cm−2 at 0.6 VRHE).
A large number of studies have focused on the role of substance P (SP) and the neurokinin-1 receptor (NK1R) in the pathogenesis of a variety of medical conditions. This review provides an overview of ...the role of the SP-NK1R pathway in the pathogenesis of musculoskeletal disorders and the evidence for its role as a therapeutic target for these disorders, which are major public health problems in most countries. To summarize, the brief involvement of SP may affect tendon healing in an acute injury setting. SP combined with an adequate conjugate can be a regenerative therapeutic option in osteoarthritis. The NK1R antagonist is a promising agent for tendinopathy, rheumatoid arthritis, and osteoarthritis. Research on the SP-NK1R pathway will be helpful for developing novel drugs for osteoporosis.
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