Amorphous NiCoB-coupled MAPbI3 for efficient photocatalytic hydrogen evolution.

It was thought that the organic-inorganic hybrid perovskite MAPbI3 could be used to collect visible light for the photocatalytic hydrogen evolution reaction (HER). However, its ability to generate H2 is limited. Herein, we synthesized amorphous NiCoB through a redox method and coupled it with MAPbI3 to form the NiCoB/MAPbI3 composite photocatalyst by electrostatic self-assembly. 30% NiCoB/MAPbI3 exhibited the maximum H2 generation yield of 2625.57 µmol g-1 h-1, which was approximately 114 fold that of pristine MAPbI3 and much better than that of Pt/MAPbI3. In addition to the excellent photocatalytic HER capability, NiCoB/MAPbI3 maintained good stability in the 24 h cycling hydrogen evolution experiment. The photoelectric analysis showed that NiCoB as a cocatalyst could realize rapid charge separation. This work can offer a reference for the construction of efficient photocatalysts based on lead halide perovskites.

Cu-Sb-S Ternary Semiconductor Nanoparticle Plasmonics.

Semiconductor plasmonics is a recently emerging field that expands the chemical and physical bandwidth of the hitherto well-established noble metallic nanoparticles. Achieving tunable plasmonics from colloidal semiconductor nanocrystals has drawn enormous interest and is promising for plasmon-related applications. However, realizing this goal of tunable semiconductor nanocrystals is currently still a synthetic challenge. Here, we report a colloidal synthesis strategy for highly dispersed, platelet-shaped, antimony-doped copper sulfide semiconductor nanocrystals (Sby-CuxS NCs) with a dominant localized surface plasmon resonance (LSPR) band tunable from the near-infrared into the midvisible spectral range. This work presents the synthesis and quantifies the resulting plasmonic features. It furthermore elucidates the underlying carrier concentration requirements to realize a continuum of LSPR spectra. Building on our previous work on binary plasmonics CuxS, CuxSe, and CuxTe NCs, the present method introduces a much wider and finer tunability with ternary semiconductor plasmonics.

Partial Cu ion exchange induced triangle hexagonal Mn0.45Cu0.05Cd0.5S nanocrystals for enhanced photocatalytic hydrogen evolution.

High crystallinity triangle hexagonal Mn0.45Cu0.05Cd0.5S was obtained by partial Cu ion exchange treatment on colloidal pristine Mn0.5Cd0.5S nanorods. The Mn0.45Cu0.05Cd0.5S nanotriangles exhibited a high hydrogen yield of 147 921 µmol g-1 h-1 under visible light irradiation, about 7.4 times higher than that of pristine Mn0.5Cd0.5S.

MoS2-Stratified CdS-Cu2-xS Core-Shell Nanorods for Highly Efficient Photocatalytic Hydrogen Production.

Heterojunction photocatalysts are widely adopted for efficient water splitting, but ion migration can seriously threaten the stability of heterojunctions, as with the well-known low stability of CdS-Cu2-xS due to intrinsic Cu+ ion migration. Here, we utilize Cu+ migration to design a stratified CdS-Cu2-xS/MoS2 photocatalyst, in which CuI@MoS2 (CuI-intercalated within the MoS2 basal plane) is created by Cu+ migration and intercalation to the adjacent MoS2 surface. The epitaxial vertical growth of the CuI@MoS2 nanosheets on the surface of one-dimensional core-shell CdS-Cu2-xS nanorods forms catalytic and protective layers to simultaneously enhance catalytic activity and stability. Charge transfer is verified by kinetics measurements with femtosecond time-resolved transient absorption spectroscopy and direct mapping of the surface charge distribution with a scanning ion conductance microscope. This design strategy demonstrates the potential of utilizing hybridized surface layers as effective catalytic and protective interfaces for photocatalytic hydrogen production.

Top-down fabrication of colloidal plasmonic MoO3-x nanocrystals via solution chemistry hydrogenation.

A high-efficiency top-down approach was used to fabricate orthorhombic MoO3-x nanocrystals through the synergic effect of oleic acid (OA) and oleylamine (OAm), in which OA provided H+ ions and OAm contributed free electrons. This investigation might provide new guidance for manipulating the optical properties of metal oxide semiconductors.

Lead-free silver-antimony halide double perovskite quantum dots with superior blue photoluminescence.

Novel all-inorganic Sb-based lead-free double perovskite Cs2AgSbX6 (X = Cl, Br or I) quantum dots exhibiting excellent air stability and strong blue emission with photoluminescence quantum yields of 31.33% were synthesized for the first time using a surfactant-assisted method. The ligand, oleic acid, could control the crystallization of the pure perovskite phase and significantly passivate the surface.

Efficient hydrogen evolution from the hydrolysis of ammonia borane using bilateral-like WO3-x nanorods coupled with Ni2P nanoparticles.

A ten times enhanced H2 evolution from the hydrolysis of ammonia borane was realized through bilateral-like plasmonic WO3-x nanorods coupled with Ni2P nanoparticles compared to Ni2P, which provides a new strategy to develop non-noble metal based plasmonic configurations for diverse energy and environment related applications.

Preparation of pristine graphene in ethanol assisted by organic salts for nonenzymatic detection of hydrogen peroxide.

High quality pristine graphene (PG) dispersions are prepared conveniently via an organic salts assisted exfoliation method in a green, non-toxic, cheap and low boiling point solvent: ethanol. The PG is characterized by transmission electron microscopy and atomic force microscopy. Furthermore, the PG is used as an electrode material for fabrication of nonenzymatic sensor of hydrogen peroxide (H2O2). This nonenzymatic sensor shows enhanced electrocatalytic activity towards H2O2 and displays two linear ranges from 2.0 to 37.0µM and 37.0 to 437.0µM with a detection limit of 0.19µM (S/N=3), which is comparable to those electrochemical sensors based on metal oxide or noble metal/graphene composites.