Transition metal oxides are being actively pursued as low-cost electrocatalysts for the oxygen evolution reaction (OER) in many electrochemical energy devices. A fundamental understanding of the oxide electronic structures, along with the ability to rationally tune them, is a key step toward designing of highly active catalysts. Here, we report the tuning of the electronic structure of NiO via Li doping (Li x Ni1–x O) to enhance the OER activities. We identified that Li0.5Ni0.5O (LiNiO2) has the highest OER activity, comparable to or exceeding that of the benchmark perovskite Ba0.5Sr0.5Co0.8Fe0.2O3−δ and LaNiO3. More importantly, a synergistic combination of synchrotron-based photoemission spectroscopy, X-ray absorption spectroscopy, and density functional theory was used to unravel the electronic structure of Li x Ni1–x O with unprecedented accuracy, thus providing deep insight into the origin of the enhanced catalytic activity. The results unambiguously reveal the creation of a new hole state at 1.1 eV above the Fermi level and an enhanced degree of O 2p–Ni 3d hybridization induced by Li doping optimize the adsorption energetics of OH intermediates and thereby facilitate the fast kinetics for the OER. The Li x Ni1–x O would serve as a new platform to study the relationship of composition–electronic structure–activity for OER electrocatalysts, beyond the extensively studied Co-based perovskites.

The chemical vapor deposition (CVD) fabrication of high-density three-dimension graphene macroscopic objects (3D-GMOs) with a relatively low porosity has not yet been realized, although they are desirable for applications in which high mechanical and electrical properties are required. Here, we explore a method to rapidly prepare the high-density 3D-GMOs using nickel chloride hexahydrate (NiCl2·6H2O) as a catalyst precursor by CVD process at atmospheric pressure. Further, the free-standing 3D-GMOs are employed as electrolytic electrodes to remove various heavy metal ions. The robust 3D structure, high conductivity (~12 S/cm) and large specific surface area (~560 m2/g) enable ultra-high electrical adsorption capacities (Cd2+ ~ 434 mg/g, Pb2+ ~ 882 mg/g, Ni2+ ~ 1,683 mg/g, Cu2+ ~ 3,820 mg/g) from aqueous solutions and fast desorption. The current work has significance in the studies of both the fabrication of high-density 3D-GMOs and the removal of heavy metal ions.

No abstract

Developing active and bifunctional noble metal-free electrocatalysts is crucial for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in the full water splitting process. A ternary nanoporous sulfur-doped copper oxide (CuOS) was successfully synthesized on Cu foam. The obtained CuOS/Cu shows robust electrocatalytic activity toward HER with a low overpotential of 40 mV at 10 mA cm and a Tafel slope of 68 mV dec and exhibits long-term stability in acid solution. Moreover, CuOS shows excellent electrocatalytic activity for OER, HER, and overall water splitting as a bifunctional catalyst in 1.0 M KOH electrolyte. The sulfur doping strategy implemented here can greatly improve the catalytic performance and stability in both acidic and alkaline water electrolyzers and presents an efficient catalyst for overall water splitting.

An organic-inorganic hybrid electrolyte based on a cyclic Ti-oxo cluster as the inorganic core and naphthalenebased organic ammonium bromide salts as the electrolyte was developed with easy synthesis and low cost. The new hybrid electrolyte exhibits excellent solubility in methanol, aligned work function, good conductivity, and amorphous state in thin film, enabling its successful application as a cathode interlayer in organic solar cells with a high power conversion efficiency of 17.19 %. This work demonstrates that the hybrid electrolytes are a new kind of semiconductor, exhibiting promising applications in organic electronics.

No abstract

No abstract

Background and AimsThe association between gallstone disease and coronary artery atherosclerotic disease (CAD) remains unclear. To clarify their relationship, patients with CAD newly diagnosed by coronary angiography were investigated in this cross-sectional study.MethodsThe study cohort consisted of 1,270 patients undergoing coronary angiography for the first time between January 2007 and September 2011. Patients with ≥50% diameter stenosis in any major coronary artery on coronary angiography were defined as being CAD positive (n = 766) and those with no stenosis as CAD negative (n = 504). Multivariate logistic regression was used to investigate the relationship between gallstone disease and CAD. The odds ratios (OR) of factors associated with CAD were calculated. In addition, CAD-positive and CAD-negative patients were matched one-to-one by age, gender and metabolic syndrome (MetS), and the association between gallbladder disease and CAD was determined.ResultsThe prevalence of gallstone disease was significantly higher in CAD-positive than in CAD negative patients (149/766 [19.5%] vs 57/504 [11.3%], P<0.01). Gallstone disease was significantly associated with CAD (adjusted OR = 1.59, 95% confidence interval [CI] 1.10–2.31). Following matched pairing of 320 patients per group, gallstone disease remained significantly associated with CAD (adjusted OR = 1.69, 95% CI: 1.08–2.65).ConclusionGallstone disease is strongly associated with CAD diagnosed by coronary angiography.