To enhance the alkaline hydrogen evolution reaction (HER), it is crucial, yet challenging, to fundamentally understand and rationally modulate potential catalytic sites. In this study, we confirm that despite calculating a low water dissociation energy barrier and an appropriate H adsorption free energy (ΔG) at Ru-top sites, metallic Ru exhibits a relatively inferior activity for the alkaline HER. This is primarily because the Ru-top sites, which are potential H adsorption sites, are recessive catalytic sites, compared with the adjacent Ru-hollow sites that have a strong ΔG.
View Article and Find Full Text PDFThe rational design of multi-site electrocatalysts with three different functions for facile HO dissociation, H-H coupling, and rapid H release is desirable but difficult to achieve. This strategy can accelerate the sluggish kinetics of the hydrogen evolution reaction (HER) under alkaline conditions. To resolve this issue, a Mo/Ru-based catalyst with three different active sites (Ru/MoC/MoO) is rationally designed and its performance in alkaline HER is evaluated.
View Article and Find Full Text PDFRegulating the catalytic reaction pathway to essentially break the activity/stability trade-off that limits RuO and thus achieves exceptional stability and activity for the acidic oxygen evolution reaction (OER) is important yet challenging. Herein, we propose a novel strategy of incorporating atomically dispersed V species, including O-bridged V dimers and V single atoms, into RuO lattices to trigger direct O-O radical coupling to release O without the generation of *OOH intermediates. V-RuO showed high activity with a low overpotential of 227 mV at 10 mA cm and outstanding stability during a 1050 h test in acidic electrolyte.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2024
Regulating competitive reaction pathways to direct the selectivity of electrochemical CO reduction reaction toward a desired product is crucial but remains challenging. Herein, switching product from HCOOH to CO is achieved by incorporating Sb element into the CuS, in which the Cu-S ionic bond is coupled with S-Sb covalent bond through bridging S atoms that elongates the Cu-S bond from 2.24 Å to 2.
View Article and Find Full Text PDFAlthough great efforts on the delicate construction of a built-in electric field (BIEF) to modify the electronic properties of active sites have been conducted, the substantial impact of BIEF coupled with electrode potential on the electrochemical reactions has not been clearly investigated. Herein, we designed an alkaline hydrogen evolution reaction (HER) catalyst composed of heterogeneous Ru-CoP urchin arrays on carbon cloth (Ru-CoP/CC) with a strong BIEF with the guidance of density functional theory (DFT) calculations. Impressively, despite its unsatisfactory activity at 10 mA cm (overpotential of 44 mV), Ru-CoP/CC exhibited better activity (357 mV) than the benchmark Pt/C catalyst (505 mV) at 1 A cm .
View Article and Find Full Text PDFEven though grain boundaries (GBs) have been previously employed to increase the number of active catalytic sites or tune the binding energies of reaction intermediates for promoting electrocatalytic reactions, the effect of GBs on the tailoring of the local chemical environment on the catalyst surface has not been clarified thus far. In this study, a GBs-enriched iridium (GB-Ir) was synthesized and examined for the alkaline hydrogen evolution reaction (HER). Operando Raman spectroscopy and density functional theory (DFT) calculations revealed that a local acid-like environment with H O intermediates was created in the GBs region owing to the electron-enriched surface Ir atoms at the GBs.
View Article and Find Full Text PDFSimultaneous optimization of the energy level of water dissociation, hydrogen and hydroxide desorption is the key to achieving fast kinetics for the alkaline hydrogen evolution reaction (HER). Herein, the well-dispersed Ru clusters on the surface of amorphous/crystalline CeO (Ru/ac-CeO ) is demonstrated to be an excellent electrocatalyst for significantly boosting the alkaline HER kinetics owing to the presence of unique oxygen vacancy (V ) and Ru Lewis acid-base pairs (LABPs). The representative Ru/ac-CeO exhibits an outstanding mass activity of 7180 mA mg that is approximately 9 times higher than that of commercial Pt/C at the potential of -0.
View Article and Find Full Text PDFThe oxygen evolution reaction (OER) is the primary bottleneck for electrochemical splitting of water into H. Developing robust and active OER electrocatalysts through understanding the OER mechanism is essential. However, the mechanism for OER is not yet well understood even for the most studied rutile Ru-based oxide, especially in a water-solvent environment.
View Article and Find Full Text PDFDeveloping electrochemical catalysts for acidic water oxidation with improved activity and stability has been the key to the further popularization of proton exchange membrane electrolyzers. In this work, an orthorhombic fluorite-type samarium iridium oxide (SmIrO) catalyst is synthesized by a simple solid-state reaction. After in situ activation, the as-prepared SmIrO exhibits higher mass activity and durability than that of commercial IrO.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2022
Synergistic optimization of the elementary steps of water dissociation and hydrogen desorption for the hydrogen evolution reaction (HER) in alkaline media is a challenge. Herein, the Ru cluster anchored on a trace P-doped defective TiO substrate (Ru/P-TiO ) was synthesized as an electrocatalyst for the HER; it exhibited a commercial Pt/C-like geometric activity and an excellent mass activity of 9984.3 mA mg at -0.
View Article and Find Full Text PDFRu nanoparticles have been demonstrated to be highly active electrocatalysts for the hydrogen evolution reaction (HER). At present, most of Ru nanoparticles-based HER electrocatalysts with high activity are supported by heteroatom-doped carbon substrates. Few metal oxides with large band gap (more than 5 eV) as the substrates of Ru nanoparticles are employed for the HER.
View Article and Find Full Text PDFThe oxygen evolution reaction (OER) is a key reaction for many electrochemical devices. To date, many OER electrocatalysts function well in alkaline media, but exhibit poor performances in neutral and acidic media, especially the acidic stability. Herein, sodium-decorated amorphous/crystalline RuO with rich oxygen vacancies (a/c-RuO ) was developed as a pH-universal OER electrocatalyst.
View Article and Find Full Text PDFRu nanoparticles (NPs) and single atoms (SAs)-based materials have been investigated as alternative electrocatalysts to Pt/C for hydrogen evolution reaction (HER). Exploring the dominant role of atomic- and nano-ruthenium as active sites in acidic and alkaline media is very necessary for optimizing the performance. Herein, an electrocatalyst containing both Ru SAs and NPs anchored on defective carbon (Ru /DC) has been synthesized via a Ru-alginate metal-organic supramolecules conversion method.
View Article and Find Full Text PDFFacilitating the dissociation of water and desorption of hydrogen are both crucial challenges for improving the hydrogen evolution reaction (HER) in alkaline media. Herein, we report the synthesis of heterostructure of Ru P/WO @NPC (N, P co-doped carbon) by a simple hydrothermal reaction using ruthenium and tungsten salts as precursors, followed by pyrolyzing under an Ar atmosphere. The Ru P/WO @NPC electrocatalyst exhibits an outstanding HER activity with an overpotential of 15 mV at a current density of 10 mA cm and excellent durability in a 1.
View Article and Find Full Text PDFExperimentally, GeS nanosheets have been successfully synthesized using vapor deposition processes and the one-pot strategy. Quite recently, GeS monolayer, the isoelectronic counterpart of phosphorene, has attracted much attention due to promising properties. By means of comprehensive first-principles calculations, we studied the stability and electronic properties of GeS monolayer.
View Article and Find Full Text PDFThe aim of this study is to investigate whether metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) can be used as a potential therapy target for human esophageal squamous cell carcinoma. MALAT-1 expression levels were detected in 137 paired EC samples and adjacent nonneoplastic tissues. Human esophageal carcinoma cell lines EC9706 and KYSE150 were transfected with MALAT-1 small interference RNA.
View Article and Find Full Text PDFAim: To study the potential prognostic role of microRNA-382 (miR-382) in esophageal squamous cell carcinoma (ESCC).
Methods: Forty six patients were divided into 2 groups according to postoperative survival time: the poor outcome group (28 patients), who showed early metastasis but no recurrence, and died within 1 year after surgery, 12 patients of the group received postoperative chemotherapy treatment that was given after early metastasis happening; the good outcome group (18 patients), who had no clinical metastasis and recurrence, and survived 5 years or more after surgery, all patients did not receive any postoperative treatment. Total RNA was extracted from the patients' formalin-fixed and paraffin-embedded esophageal cancer tissues.
Zhonghua Zhong Liu Za Zhi
February 2015
Objective: The aim of this study was to explore the influencing factors of prognosis for recurrent and metastatic esophageal carcinoma, and to provide reference for clinical treatment for these patients.
Methods: The clinicopathological and follow-up data of 247 patients with recurrent and metastatic esophageal squamous cell carcinoma after radical resection were retrospectively reviewed, combined with analysis of prognostic factors in these patients. Kaplan-Meier method was used to analyze the survival, difference between groups was compared by Log rank test, and Cox model was used for multivariate analysis.
It has been well accepted that p53 overexpression is associated with advanced stages of cancer. However, the prognostic role of p53 overexpression in esophageal squamous cell carcinoma (ESCC) remains unclear. To investigate the prognostic role of p53 overexpression in patients with ESCC, a retrospective cohort study of 136 ESCC patients was carried out.
View Article and Find Full Text PDFObjective: The aim of this study was to explore the expression of activin A in esophageal squamous cell carcinoma and its clinical significance.
Methods: Immunohistochemical (IHC) staining was used for detecting the expression of tissue activin A in sixty-four patients with esophageal squamous cell carcinoma, and enzyme-linked immunosorbent assay (ELISA) was used for detecting the serum activin A in the patients before and after surgery. The relationship between expression of activin A in the esophageal cancer tissue with clinicopathological features and its influence on prognosis were analyzed.
Asian Pac J Cancer Prev
December 2014
Objective: This study aimed to investigate whether the miR-198 expression level is related to clinicopathological factors and prognosis of esophageal cancer.
Methods: MicroRNA was extracted from esophageal cancer patients who underwent surgery for assessment using the Taqman@ MicroRNA assay. The correlation between miR-198 expression and clinicopathological features was analyzed, and the significance of miR-198 as a prognostic factor and its relationship with survival was determined.
The aim of this study was to explore the association of specific microRNAs (miRNAs) with the development of esophageal cancer (EC) and to identify new molecular markers for EC by analyzing the expression profiles of miRNAs in EC tissues. The expression profiles of miRNAs in paired EC and paracancerous normal tissues were detected and bioinformatically analyzed using miRNA assays. The outcomes were validated using real-time polymerase chain reaction.
View Article and Find Full Text PDFPatients at the same pathological stage of esophageal cancer (EC) that received the same surgical therapy by the same surgeon may have distinct prognoses. The current study aimed to explore the possibility of differentially- expressed microRNAs (miRNAs) underlying this phenomenon. Samples were collected from EC patients at the same tumor node metastasis (TNM) stage but with different prognoses.
View Article and Find Full Text PDF