The
development of highly efficient and durable electrocatalysts
for high-performance overall water-splitting devices is crucial for
clean energy conversion. However, the existing electrocatalysts still
suffer from low catalytic efficiency, and need a large overpotential
to drive the overall water-splitting reactions. Herein, we report
an iridium–tungsten alloy with nanodendritic structure (IrW
ND) as a new class of high-performance and pH-universal bifunctional
electrocatalysts for hydrogen and oxygen evolution catalysis. The
IrW ND catalyst presents a hydrogen generation rate ∼2 times
higher than that of the commercial Pt/C catalyst in both acid and
alkaline media, which is among the most active hydrogen evolution
reaction (HER) catalysts yet reported. The density functional theory
(DFT) calculations reveal that the high HER intrinsic catalytic activity
results from the suitable hydrogen and hydroxyl binding energies,
which can accelerate the rate-determining step of the HER in acid
and alkaline media. Moreover, the IrW NDs show superb oxygen evolution
reaction (OER) activity and much improved stability over Ir. The theoretical
calculation demonstrates that alloying Ir metal with W can stabilize
the formed active iridium oxide during the OER process and lower the
binding energy of reaction intermediates, thus improving the Ir corrosion
resistance and OER kinetics. Furthermore, the overall water-splitting
devices driven by IrW NDs can work in a wide pH range and achieve
a current density of 10 mA cm–2 in acid electrolyte
at a low potential of 1.48 V.
The rational design of photocatalysts for efficient nitrogen (N 2 ) fixation at ambient conditions is important for revolutionizing ammonia production and quite challenging because the great difficulty lies in the adsorption and activation of the inert N 2 . Inspired by a biological molecule, chlorophyll, featuring a porphyrin structure as the photosensitizer and enzyme nitrogenase featuring an iron (Fe) atom as a favorable binding site for N 2 via π-backbonding, here we developed a porphyrin-based metal−organic framework (PMOF) with Fe as the active center as an artificial photocatalyst for N 2 reduction reaction (NRR) under ambient conditions. The PMOF features aluminum (Al) as metal node imparting high stability and Fe incorporated and atomically dispersed by residing at each porphyrin ring promoting the adsorption and the activation of N 2 , termed Al-PMOF(Fe). Compared with the pristine Al-PMOF, Al-PMOF(Fe) exhibits a substantial enhancement in NH 3 yield (635 μg g −1 cat. ) and production rate (127 μg h −1 g −1 cat. ) of 82% and 50%, respectively, on par with the best-performing MOF-based NRR catalysts. Three cycles of photocatalytic NRR experimental results corroborate a stable photocatalytic activity of Al-PMOF(Fe). The combined experimental and theoretical results reveal that the Fe−N site in Al-PMOF(Fe) is the active photocatalytic center that can mitigate the difficulty of the rate-determining step in photocatalytic NRR. The possible reaction pathways of NRR on Al-PMOF(Fe) were established. Our study of porphyrin-based MOF for the photocatalytic NRR will provide insight into the rational design of catalysts for artificial photosynthesis.
Chemotherapy-induced peripheral neuropathy (CIPN) is a severe, toxic side effect that frequently occurs in anticancer treatment and may result in discontinuation of treatment as well as a serious reduction in life quality. The CIPN incidence rate is as high as 85–90%. Unfortunately, there is currently no standard evidence-based CIPN treatment. In several clinical trials, it has been reported that duloxetine can improve CIPN pain induced by oxaliplatin (OXA) and paclitaxel (PTX); thus, The American Society of Clinical Oncology (ASCO) recommends duloxetine as the only potential treatment for CIPN. However, this guidance lacks the support of sufficient evidence. Our study shows that duloxetine markedly reduces neuropathic pain evoked by OXA or PTX. Duloxetine acts by inhibiting the activation of p38 phosphorylation, thus preventing the activation and nuclear translocation of the NF-κB transcription factor, reducing the inflammatory response and inhibiting nerve injury by regulating nerve growth factor (NGF). Furthermore, in this study, it is shown that duloxetine does not affect the antitumor activity of OXA or PTX. This study not only provides biological evidence to support the use of duloxetine as the first standard CIPN drug but will also lead to potential new targets for CIPN drug development.
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