Sulfur occupancy-induced construction of ant-nest-like NiMo/CF(N) electrode for highly efficient hydrogen evolution.

The microstructure of the electrocatalyst plays a critical role in the reaction efficiency and stability during electrochemical water splitting. Designing an efficient and stable electrocatalyst, further clarifying the synthesis mechanism, is still an important problem to be solved urgently. Inspired by the copper pyrometallurgy theory, an exceptionally active NiMo/CF(N) electrode, consisting of an ant-nest-like copper foam substrate (defined as CF(N)) and deposited NiMo layer, was fabricated for the alkaline hydrogen evolution reaction (HER). Our findings expounded the structure construction mechanism and highlighted the pivotal role of the spatial occupancy of sulfur atoms in the construction of the ant-nest-like structure. The NiMo/CF(N) composite, characterized by channels with a 2 µm diameter, showcases strong electronic interactions, increased catalytic active sites, enhanced electron/ion transport, and facilitated gas release during HER. Remarkably, NiMo/CF(N) demonstrates ultralow overpotentials of 21 mV to deliver a current density of 10 mA cm-2 in 1 M KOH. This electrode also exhibits outstanding durability, maintaining a current density of 200 mA cm-2 for 110 h, attributed to the chemical and structural integrity of its catalytic surface and the excellent mechanical properties of the electrode. This work advances the fundamental understanding of constructing micro/nano-structured electrocatalysts for highly efficient water splitting.

Deep Eutectic Solvent-Assisted Corrosion Boosting Bulk FeCoNiCrMo High-Entropy Alloys as Highly Efficient Oxygen Evolution Reaction Catalyst.

The key to enhancing water electrolysis efficiency lies in selecting highly efficient catalysts. Currently, high-entropy alloys (HEAs) are utilized in electrocatalysis applications owing to their diverse elemental composition, disordered elemental distribution, and the high solubility of each element, endowing them with excellent catalytic performance. The experiments were conducted using isoatomic FeNiCrMo HEA as a precursor, with a high-activity three-dimensional nanoporous structure rapidly synthesized via electrochemical one-step dealloying in a choline chloride-thiourea (ChCl-TU) deep eutectic solvent (DES). The results indicate that the dealloyed Fe20Co20Ni20Cr20Mo20 HEA mainly consists of two phases: face-centered cubic and σ phases. The imbalance in the distribution of elements in these two phases leads to quite different corrosion speeds with the FCC phase being preferentially corroded. Furthermore, synergistic electron coupling between surface atoms in the three-dimensional nanoporous structure strengthens the behavior of the oxygen evolution reaction (OER). At a current density of 40 mA cm-2, the overpotential after dealloying decreased to 370 mV, demonstrating excellent stability. The technique demonstrated in this work provides a novel approach to improve the catalytic activity of OER.

Bubble Management for Electrolytic Water Splitting by Surface Engineering: A Review.

During electrocatalytic water splitting, the management of bubbles possesses great importance to reduce the overpotential and improve the stability of the electrode. Bubble evolution is accomplished by nucleation, growth, and detachment. The expanding nucleation sites, decreasing bubble size, and timely detachment of bubbles from the electrode surface are key factors in bubble management. Recently, the surface engineering of electrodes has emerged as a promising strategy for bubble management in practical water splitting due to its reliability and efficiency. In this review, we start with a discussion of the bubble behavior on the electrodes during water splitting. Then we summarize recent progress in the management of bubbles from the perspective of surface physical (electrocatalytic surface morphology) and surface chemical (surface composition) considerations, focusing on the surface texture design, three-dimensional construction, wettability coating technology, and functional group modification. Finally, we present the principles of bubble management, followed by an insightful perspective and critical challenges for further development.

Decomposition behavior and reaction mechanism of Ce0.67Tb0.33MgAl11O19 during Na2CO3 assisted roasting: Toward efficient recycling of Ce and Tb from waste phosphor.

Waste aluminate phosphor is a valuable secondary resource of rare earth elements (REEs). However, Ce and Tb in aluminate green phosphor can hardly be extracted by direct leaching in an inorganic acid. Therefore, Na2CO3 assisted roasting is adopted to decompose the stable spinel structure of Ce0.67Tb0.33MgAl11O19 in the present work and to achieve the transformation of REEs to simple oxides. Based on the thermodynamic calculations, systematic experiments of thermal decomposition have been conducted. The thermal decomposition behavior, phase evolution, valence state change, variations in micro and macro morphology of the green phosphor during Na2CO3 assisted roasting were examined by using TG-DSC/MS, XRD, XPS, SEM/EDS analyses. The results indicated that the green phosphor began to react with solid Na2CO3 at 800 °C, and the reaction was dramatically accelerated with temperature rising above 851 °C. At about 1000 °C, Ce0.67Tb0.33MgAl11O19 could completely decomposed into CeO2, Tb2O3 and MgO by roasting in an equivalent mass of Na2CO3 for 2 h, while α-Al2O3 was hardly attacked in roasting. The decomposition mechanism of Ce0.67Tb0.33MgAl11O19 in molten Na2CO3 could be depicted by the unreacted shrinking core model, and the reaction rate constant was estimated at approximately nanometers per second. The synergistic effect of cation-oxoanion ensures the successful extraction of CeO2 and Tb2O3 from the green phosphor via Na2CO3 assisted roasting method. The converted CeO2 and Tb2O3 can be extracted by using chlorination roasting and separated from non-REE residues. According to these investigations, a new efficient process technology is proposed for sustainable recycling of waste phosphor.

Effect of Remote Internet Follow-Up on Postradiotherapy Compliance Among Patients with Esophageal Cancer: A Randomized Controlled Study.

BACKGROUND: To explore the effects of using remote Internet follow-up on postradiotherapy compliance with medical advice provided to patients with esophageal cancer. PATIENTS AND METHODS: Between January 1 and August 1, 2013, in total, 128 patients with esophageal squamous cell cancer treated with radiotherapy were randomly assigned to either an observation group (n=64) or a control group (n=64). The control group received routine outpatient follow-up, whereas the observation group received additional remote Internet follow-up for 6 months after discharge from the hospital. The treatment effects and compliance were investigated using a questionnaire. RESULTS: At 3 months and 6 months after discharge, patients in the observation group had sought significantly more consultations and undergone more periodic re-examinations than patients in the control group (all p<0.001). Furthermore, both the disease-free survival rate and the symptom reduction rate were significantly higher in the observation group compared with the control group (all p<0.001). CONCLUSIONS: Remote Internet follow-up is an easy and fast method for improving postradiotherapy compliance with medical instructions and promoting normalization among patients with esophageal cancer.