Archaean multi-stage magmatic underplating drove formation of continental nuclei in the North China Craton.

The geodynamic processes that formed Earth's earliest continents are intensely debated. Particularly, the transformation from ancient crustal nuclei into mature Archaean cratons is unclear, primarily owing to the paucity of well-preserved Eoarchaean-Palaeoarchaean 'protocrust'. Here, we report a newly identified Palaeoarchaean continental fragment-the Baishanhu nucleus-in northeastern North China Craton. U-Pb geochronology shows that this nucleus preserves five major magmatic events during 3.6-2.5 Ga. Geochemistry and zircon Lu-Hf isotopes reveal ancient 4.2-3.8 Ga mantle extraction ages, as well as later intraplate crustal reworking. Crustal architecture and zircon Hf-O isotopes indicate that proto-North China first formed in a stagnant/squishy lid geodynamic regime characterised by plume-related magmatic underplating. Such cratonic growth and maturation were prerequisites for the emergence of plate tectonics. Finally, these data suggest that North China was part of the Sclavia supercraton and that the Archaean onset of subduction occurred asynchronously worldwide.

Promotional effects of In(PO3)3 on the high catalytic activity of CuO-In(PO3)3/C for the CO2 reduction reaction.

The construction of Cu-In bi-component catalysts is an effective strategy to enhance the electrocatalytic properties towards the CO2 reduction reaction (CO2RR). However, realizing the co-promotion of In and heteroatom P on the electrocatalytic performance is still a challenge due to the poor selectivity of metal phosphides. Herein, a novel bi-component catalyst (CuO-In(PO3)3/C) was successfully synthesized via a facile one-pot reaction to realize the integration of Cu, In, and P species for the enhancement of electrocatalysis. In particular, the as-obtained nanorod-like Cu-In(PO3)3/C exhibits superior electrocatalysis towards the CO2RR, with the highest Faraday efficiency of CO (FECO) of 88.5% at -0.586 V. Furthermore, Cu-In(PO3)3/C shows better activity, selectivity, and stability in the CO2RR; in particular, the total current density can reach 178.09 mA cm-2 at -0.886 V in 2.0 M KOH solution when a flow cell is employed. This work provides a reliable method for simplifying the synthesis of novel Cu-based catalysts and exploits the application of heteroatom P in the field of efficient CO2RR.

Elaborate tree-like Cu-Ag clusters from green electrodeposition for efficiently electrocatalyzing CO2 conversion into syngas.

The electrocatalytic carbon dioxide reduction (CO2RR) is one of the emerging technologies that can effectively transform carbon dioxide (CO2) into valuable products. Electrocatalysts deriving from green synthesis methods will significantly help to establish a new green carbon cycle. Herein, a green electrodeposition method without additional reducing agents was used to synthesize Cu-Ag bimetallic catalysts, and it is shown that the combination of Cu and Ag obviously affects the morphology of the Cu-Ag catalysts, resulting in the formation of elaborate tree-like Cu-Ag clusters. An as-deposited Cu-Ag/carbon fiber (Cu-Ag/CF) catalyst exhibits high activity, selectivity and stability toward the CO2RR; in particular, the elaborate dendritic Cu-Ag/CF can efficiently reduce CO2 to syngas with high selectivity (Faradaic efficiency (FE) > 95%) at a low onset potential (-0.5 V). This work provides a rational strategy to overcome the significantly different reaction capacities during the reduction of Ag+ and Cu2+, leading to the formation of a controlled morphology of Cu-Ag, which is favourable for the design and development of highly efficient Cu or Ag catalysts via green methods for electrocatalyzing the CO2RR.

Mo2C promoted electrocatalysis of the Pt/Mo2C (C) heterostructure for a superior hydrogen evolution reaction.

Constructing a unique electrochemical interface to enhance the catalytic capacity of Pt-based catalysts is indispensable for wider application of the hydrogen evolution reaction (HER). Herein, platinum-analogous molybdenum carbide (Mo2C) was combined with a lower content of Pt to construct the Pt/Mo2C (C) heterostructure via a solid-phase method, using ammonium molybdate as the precursor. Vulcan-C served as a support to promote the distribution of the Pt and Mo2C heterostructure, and cooperative effects between Pt and the Mo2C heterostructure contributed to the significantly improved catalytic capacity of Pt. The obtained Pt/Mo2C (C) exhibits superior HER activity and enhanced long-term durability in the acidic medium, with a low overpotential of 38 mV at 10 mA cm-2 and a low Tafel slope of 24 mV dec-1. In particular, a drastically enhanced amount of H2 production can be achieved (6837.28 mmol h-1 g-1). This facile approach not only provides a new pathway for constructing novel heterostructures but also gives an insight into the design of cost-effective Pt-based materials for an efficient HER.

Highly selective and active Cu-In2O3/C nanocomposite for electrocatalytic reduction of CO2 to CO.

The Cu-In2O3/C nanocomposite was prepared by a simple solid-phase reduction method. The introduction of In2O3 into Cu/C to form the Cu-In2O3/C nanocomposite evidently enhances the electrocatalytic activity for the selective reduction of CO2 to CO. Specifically, the Cu-In2O3/C nanocomposite exhibits higher Faraday efficiency (FE = 86.7%) at -0.48 V vs. the reversible hydrogen electrode (RHE) in the electrocatalytic reduction of CO2 to CO and larger current densities (55 mA cm-2) under a low overpotential (-1.08 V vs. RHE). These indicate its superior performance over many of the reported Cu-based catalysts [1-4]. It was also found that by rationally adjusting the applied potential, tunable syngas can be formed, which can be used to synthesize formic acid, methyl ether, methanol, synthetic fuels, or other bulk chemicals through appropriate industrial processes. Furthermore, the Cu-In2O3/C nanocomposite maintains good stability in the electrocatalytic reduction of CO2. This work demonstrates a novel strategy to convert CO2 into desired products with high energy efficiency and large current density under low overpotential by the rational designing of non-precious metal catalysts.

Synthesis of Pt-Ni (trace)/GNs composite and its bi-functional electrocatalytic properties for MOR and ORR.

An aqueous solution synthesis method was used to synthesize a Pt-Ni/GNs composite containing trace amounts of Ni species by the aid of self-etching or acid-etching process. Its component structure and morphology were characterized by X-ray diffraction (XRD), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), Inductively Coupled Plasma-Atomic Emission Spectroscopy(ICP-AES) and Raman spectra, etc. The obvious cracked Pt-Ni nanoclusters can be found in Pt-Ni (trace)/GNs which contains only trace Ni species. Electrochemical experiments indicate that Pt-Ni (trace)/GNs exhibits bi-functional electrocatalytic performance for MOR and ORR with the mass activity of 1009.98 mA mg-1 and 157.7 mA mg-1, respectively, which is superior to commercial Pt-Ru/C-JM. It is proven that the trace Ni species contribute to the enhanced electrocatalytic performance of the Pt-Ni/GNs composite.

A green one-pot synthesis of Pt/TiO2/Graphene composites and its electro-photo-synergistic catalytic properties for methanol oxidation.

A facile and green one-pot method was used to synthesize Pt/TiO2/Graphene composites with ethanol as a reducing agent under microwave irradiation. The as-prepared composites were characterized by SEM, TEM, EDX, XPS, XRD and Raman. Electrocatalytic performance of the Pt/TiO2/GNs composites was investigated by cyclic voltammetry (CV), chronoamperometric (CA), COad stripping voltammetry and electrochemical impedance spectrum (EIS). All experimental data have revealed that TiO2 (P25) not only enhanced the reduction ability of ethanol under microwave irradiation but also promoted Pt heterogeneous nucleation to form Pt nanoclusters which are around P25 and loaded on graphene nanosheets (GNs) surface. Electrochemical experiments showed that Pt/TiO2/GNs had much higher catalytic activity and stability toward methanol oxidation reaction (MOR) and better resistance to CO poisoning compared with Pt/GNs and the commercially available Johnson Matthey 20% Pt/C catalyst (Pt/C-JM). Especially under UV irradiation with 20min, Pt/TiO2/GNs composites showed an ultrahigh forward peak current density of 1354mAmg(-1), nearly 2.5 times higher than that of Pt/C-JM, which indicated that the electrocatalytic and photocatalytic properties of Pt/TiO2/GNs had been integrated to boost the catalytic performance for MOR.

Preparation of Pt/{PDDA-GN/PSS-GN}n multilayer films and their electrocatalytic activity regarding methanol oxidation.

The stable aqueous dispersion solutions of polymer-modified graphene were prepared by reduction with hydrazine hydrate in situ from exfoliated graphite oxides in the presence of poly (diallyldimethylammonium chloride) (PDDA) and poly(sodium 4-styrenesulfonate) (PSS), respectively. The multilayer films consisting of PDDA-GN and PSS-GN were fabricated on the substrate by layer-by-layer self-assembly technique and characterized by ultraviolet-visible spectroscopy (UV-vis). The multilayer films were used as a novel catalyst support for electrodeposition of Pt nanoparticle clusters in situ. X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FE-SEM), and X-ray diffraction (XRD) analysis demonstrated that Pt particles had been immobilized on the surface of {PDDA-GN/PSS-GN}(n) multilayer films. Cyclic voltammetry and chronoamperometric curves were used to study electrocatalytic activity of Pt/{PDDA-GN/PSS-GN}(n) multilayer films regarding methanol oxidation. The results indicated good electrocatalytic activity of the titled multilayer composites toward methanol oxidation in the 0.5 M H(2)SO(4).

In situ electro-deposition of Pt micro-nano clusters on the surface of {[PMo12O40]3-/PAMAM}n multilayer composite films and their electrocatalytic activities regarding methanol oxidation.

The {[PMo(12)O(40)](3-)/PAMAM}(n) multilayer films are prepared by LBL electrostatic assembly technique, and their uniform and homogeneous traits have been verified by cyclic voltammetry. The {[PMo(12)O(40)](3-)/PAMAM}(n) multilayer films with PAMAM as the outmost layer, having an open structure and exhibiting good penetrability for the solvent molecules at low pH, are used as matrices for electro-deposition of Pt micro-nano clusters in situ. X-ray photoelectron spectroscopy (XPS) analysis and field emission scanning electron microscope (FE-SEM) characterization show that the unique Pt micro-nano clusters with flower-like structure have been immobilized on the surface of {[PMo(12)O(40)](3-)/PAMAM}(n) multilayer films. The morphologies of Pt micro-nano clusters are influenced by electro-deposition conditions such as deposition potential, deposition time, and the number of layers of {[PMo(12)O(40)](3-)/PAMAM}(n) multilayer films. Pt(-clusters)-{PMo(12)/PAMAM}(3) composite films demonstrate good electrocatalytic activities regarding methanol oxidation and improved tolerance of CO.

(2-Amino-phen-yl)methyl-diphenyl-phospho-nium iodide.

The asymmetric unit of the title compound, C(19)H(19)NP(+)·I(-), contains two tetra-alkyl-phospho-nium cations and two I(-) anions. The P atoms are four-coordinated in distorted tetra-hedral configurations by three phenyl and one methyl C atoms. There are weak intra- and inter-molecular N-H⋯I contacts.