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Recently, electrochemical nitrate reduction reaction (NO3RR) has been intensively explored for the synthesis of ammonia, and copper (Cu) has become one of the most promising materials for NO3RR. Notably, Cu is an important plasmonic metal that absorbs visible light. The plasmonic effect might have a significant influence on the performance of Cu-catalyzed NO3RR but has been seldom reported. Herein, we report the synergistic photoelectric and thermal effect for efficient and stable NO3RR on plasmonic Cu nanowire photocathodes, which is exclusively effective for NO3RR but has no effect on the competing hydrogen evolution reaction. The faradaic efficiency for ammonia production is nearly 100% within a potential range from –0.2 V to –0.4 V vs. RHE, and a high ammonia yield rate of 1.37 mmol h–1cm–2is achieved at –0.2 V vs. RHE. Further operando photoelectrochemical studies and theoretical simulations confirm that the plasmonic excitation efficiently accelerates the rate-limiting desorption of NH3on Cu surfaces. We further demonstrate the versatility of this strategy to other Cu-based nanostructures.

Epoxides are one of the most important intermediates used in the production of valuable chemicals. Traditional preparation methods often rely on hazardous oxidants or extensive fossil fuel-powered thermal catalytic systems, resulting in significant waste production and CO2emissions. Solar-driven photo(electro)chemistry is an emerging option for achieving the environmentally-friendly synthesis of epoxides. In this review, we firstly summarize the fundamental understanding of epoxidation reactions among various systems, including molecular catalysis, heterogeneous thermal catalysis and electrocatalysis. Then, we focus on the recent advances in the synthesis of epoxides achieved by photo(electro)chemical approaches. This review is concluded by the rational design of photoelectrochemical systems towards efficient epoxide synthesis.

Accelerating proton transfer has been demonstrated as key to boosting water oxidation on semiconductor photoanodes. Herein, we study proton-coupled electron transfer (PCET) of water oxidation on five typical photoanodes [i.e., α-Fe2O3, BiVO4, TiO2, plasmonic Au/TiO2, and nickel–iron oxyhydroxide (Ni1–xFexOOH)-modified silicon (Si)] by combining the rate law analysis of H2O molecules with the H/D kinetic isotope effect (KIE) and operando spectroscopic studies. An unexpected and universal half-order kinetics is observed for the rate law analysis of H2O, referring to a sequential proton–electron transfer pathway, which is the rate-limiting factor that causes the sluggish water oxidation performance. Surface modification of the Ni1–xFexOOH electrocatalyst is observed to break this limitation and exhibits a normal first-order kinetics accompanied by much enhanced H/D KIE values, facilitating the turnover frequency of water oxidation by 1 order of magnitude. It is the first time that Ni1–xFexOOH is found to be a PCET modulator. The rate law analysis illustrates an effective strategy for modulating PCET kinetics of water oxidation on semiconductor surfaces.

The water oxidation half-reaction at anodes is always considered the rate-limiting step of overall water splitting (OWS), but the actual bias distribution between photoanodes and cathodes of photoelectrochemical (PEC) OWS cells has not been investigated systematically. In this work, we find that, for PEC cells consisting of photoanodes (nickel-modified n-Si [Ni/n-Si] and α-Fe2O3) with low photovoltage (Vph< 1 V), a large portion of applied bias is exerted on the Pt cathode for satisfying the hydrogen evolution thermodynamics, showing a thermodynamics-controlled characteristic. In contrast, for photoanodes (TiO2and BiVO4) with Vph> 1 V, the bias required for cathode activation can be significantly reduced, exhibiting a kinetics-controlled characteristic. Further investigations show that the bias distribution can be regulated by tuning the electrolyte pH and using alternative half-reaction couplings. Accordingly, a volcano plot is presented for the rational design of the overall reactions and unbiased PEC cells. Motivated by this, an unbiased PEC cell consisting of a simple Ni/n-Si photoanode and Pt cathode is assembled, delivering a photocurrent density of 5.3 ± 0.2 mA cm−2.This work reveals a general rule for measuring and describing the bias distribution in photoelectrochemical overall reaction cells, which inspires the rational design for high-performance unbiased photoelectrochemical cells in diversified practical scenarios.

Hypoxia in the tumor microenvironment (TME) greatly limits the tumor-killing therapeutic efficacy of sonodynamic therapy (SDT); this phenomenon is further exacerbated by increased glutathione (GSH) levels in cancer cells. Simultaneously, cancer starvation therapy is increasingly recognized nowadays as a promising clinical translation, but the efficacy of glucose oxidase (GOx)-based starvation therapy is also limited by the lack of oxygen in the tumor. Glycer-aldehyde-3-phosphate dehydrogenase (GAPDH) is a key glycolytic enzyme and can therefore be a target for starvation therapy in the absence of oxygen engagement. Here, we proposed thiol-ene click reactions based on a two-dimensional metal-organic framework (MOF) modification for tumor treatments to enable the combination of SDT and starvation therapy. Experimental studies demonstrated that the prepared material could consume GSH and GAPDH free from oxygen in TME, which benefited from the thiol-ene click reactions between the MOFs and thiol substances in cancer cells. Further experiments in vitroand in vivoindicated the prepared MOF materials could kill cancer cells efficiently. This study is expected to create a promising avenue for thiol-ene click reactions in SDT and starvation therapy for cancer.

Laboratory weight-loss measurements, electrochemical tests and SEM techniques were used to study the corrosive behaviour of electrolysed ballast water on marine carbon steel. Experimental results showed that for the mass concentration of Total Residual Chlorine (TRC) being 7.5mg/l, 17mg/l and 28mg/l respectively, the corrosion rates within seven days were 1.25, 1.46 and 1.7 times those in natural seawater. The corrosion rates decreased as time progressed. The corrosion rate in the electrolysed seawater is controlled by the cathodic process which is mass transfer controlled. The SEM observation showed that the topographies of carbon steel corroded in electrolysed ballast water with mass concentration of TRC 7.5mg/l and 17mg/l were characterised by denudation and rupture. Both the weight-loss and electrochemical tests revealed that the chlorinated seawater accelerated the corrosion rate and that this is consistent with result of the SEM observation

Marine engineering, applying engineering sciences, mostly mechanical and electrical engineering, to the development design, operation and maintenance of the vessels. China and the United States have made rapid progresses in the maritime development for decades, among which, the development in marine engineering between two countries is analyzed and compared through maritime education, training ships, etc in this paper. It is found that there are many differences in selecting the marine propulsion and transmission system, sea practice and ship types and so on.