Highly active, stable, and cheap Pt-free catalysts for the hydrogen evolution reaction (HER) are facing increasing demand as a result of their potential use in future energy-conversion systems. However, the development of HER electrocatalysts with Pt-like or even superior activity, in particular ones that can function under alkaline conditions, remains a significant challenge. Here, the synthesis of a novel carbon-loaded ruthenium nanoparticle electrocatalyst (Ru@CQDs) for the HER, using carbon quantum dots (CQDs), is reported. Electrochemical tests reveal that, even under extremely alkaline conditions (1 m KOH), the as-formed Ru@CQDs exhibits excellent catalytic behavior with an onset overpotential of 0 mV, a Tafel slope of 47 mV decade , and good durability. Most importantly, it only requires an overpotential of 10 mV to achieve the current density of 10 mA cm . Such catalytic characteristics are superior to the current commercial Pt/C and most noble metals, non-noble metals, and nonmetallic catalysts under basic conditions. These findings open a new field for the application of CQDs and add to the growing family of metal@CQDs with high HER performance.

Ac hallenging but pressing task to design and synthesize novel, efficient, and robust pH-universal hydrogen evolution reaction (HER) electrocatalysts for scalable and sustainable hydrogen production through electrochemical water splitting.H erein, we report af acile method to prepare an efficient and robust Ru-M (M = Ni, Mn, Cu) bimetal nanoparticle and carbon quantum dot hybrid (RuM/CQDs) for pH-universal HER. The RuNi/CQDs catalysts exhibit outstanding HER performance at all pH levels.The unexpected low overpotentials of 13, 58, and 18 mV shown by RuNi/ CQDs allowacurrent density of 10 mA cm À2 in 1m KOH, 0.5 m H 2 SO 4 ,a nd 1m PBS,r espectively,f or Ru loading at 5.93 mgRu cm À2 .T his performance is among the best catalytic activities reported for any platinum-free electrocatalyst. Theoretical studies reveal that Ni doping results in am oderate weakening of the hydrogen bonding energy of nearby surface Ru atoms,w hich playsac ritical role in improving the HER activity.

Intracardiac leiomyomatosis is rare but has been increasingly reported in recent years. Owing to its rarity, intracardiac leiomyomatosis has been reported only as isolated case reports and case series. This disorder is thought to be underestimated and easily overlooked in the clinic, while it is dangerous owing to the risk of sudden death caused by total outflow tract obstruction. We performed an electronic literature search for intracardiac leiomyomatosis and identified 194 cases that were reported in English from 1974 (the first reported case) to September 2012. Our aim is to provide a detailed and comprehensive review of the clinical presentation, diagnosis, histopathological characterization, treatment and prognosis of this disorder. According to our analysis, intracardiac leiomyomatosis is most common in the fifth decade, and the mean age of detection is ~50 years. Most patients had undergone previous hysterectomy/myomectomy or had a coexisting uterine leiomyoma when admitted. The most common clinical presentations were dyspnoea, syncope, oedema of the lower extremities and palpitation. Transoesophageal echocardiography, computed tomography and magnetic resonance imaging are helpful in the preoperative diagnosis and to guide the surgical management. Complete removal guarantees an excellent outcome, with no recurrence or postoperative death, while incomplete removal leads to recurrence in one-third of patients. Anti-oestrogen therapy is not imperative after incomplete removal owing to its inability to prevent recurrence.

Designing bifunctional catalysts capable of driving the electrochemical hydrogen evolution reaction (HER) and also H2 evolution via the hydrolysis of hydrogen storage materials such as ammonia borane (AB) is of considerable practical importance for future hydrogen economies. Herein, we systematically examined the effect of tensile lattice strain in CoRu nanoalloys supported on carbon quantum dots (CoRu/CQDs) on hydrogen generation by HER and AB hydrolysis. By varying the Ru content, the lattice parameters and Ru‐induced lattice strain in the CoRu nanoalloys could be tuned. The CoRu0.5/CQDs catalyst with an ultra‐low Ru content (1.33 wt.%) exhibited excellent catalytic activity for HER (η=18 mV at 10 mA cm−2 in 1 M KOH) and extraordinary activity for the hydrolysis of AB with a turnover frequency of 3255.4 mol(normalH2)  mol−1(Ru) min−1 or 814.7 mol(normalH2)  mol−1(cat) min−1 at 298 K, respectively, representing one of the best activities yet reported for AB hydrolysis over a ruthenium alloy catalyst. Moreover, the CoRu0.5/CQDs catalyst displayed excellent stability during each reaction, including seven alternating cycles of HER and AB hydrolysis. Theoretical calculations revealed that the remarkable catalytic performance of CoRu0.5/CQDs resulted from the optimal alloy electronic structure realized by incorporating small amounts of Ru, which enabled fast interfacial electron transfer to intermediates, thus benefitting H2 evolution kinetics. Results support the development of new and improved catalysts HER and AB hydrolysis.

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Featuring a high theoretical capacity, low cost, and abundant resources, sodium metal has emerged as an ideal anode material for sodium ion batteries. However, the real feasibility of sodium metal anodes is still hampered by the uncontrolled sodium dendrite problems. Herein, an artificial three-dimensional (3D) hierarchical porous sodiophilic V2CT x /rGO-CNT microgrid aerogel is fabricated by a direct-ink writing 3D printing technology and further adopted as the matrix of Na metal to deliver a Na@V2CT x /rGO-CNT sodium metal anode. Upon cycling, the V2CT x /rGO-CNT electrode can yield a superior cycling life of more than 3000 h (2 mA cm–2, 10 mAh cm–2) with an average Coulombic efficiency of 99.54%. More attractively, it can even sustain a stable operation over 900 h at 5 mA cm–2 with an ultrahigh areal capacity of 50 mAh cm–2. In situ and ex situ characterizations and density functional theory simulation analyses prove that V2CT x with abundant sodiophilic functional groups can effectively guide the sodium metal nucleation and uniform deposition, thus enabling a dendrite-free morphology. Moreover, a full cell pairing a Na@V2CT x /rGO-CNT anode with a Na3V2(PO4)3@C-rGO cathode can deliver a high reversible capacity of 86.27 mAh g–1 after 400 cycles at 100 mA g–1. This work not only clarifies the superior Na deposition chemistry on the sodiophilic V2CT x /rGO-CNT microgrid aerogel electrode but also offers an approach for fabricating advanced Na metal anodes via a 3D printing method.