Schottky Junction Enhanced Photosynthesis of Hydrogen Peroxide by Ultrathin Porous Carbon Nitride Supported Ni Nanoparticles.

Artificial photosynthesis for high-value hydrogen peroxide (H2O2) through a two-electron reduction reaction is a green and sustainable strategy. However, the development of highly active H2O2 photocatalysts is impeded by severe carrier recombination, ineffective active sites, and low surface reaction efficiency. We developed a dual optimization strategy to load dense Ni nanoparticles onto ultrathin porous graphitic carbon nitride (Ni-UPGCN). In the absence and presence of sacrificial agents, Ni-UPGCN achieved H2O2 production rates of 169 and 4116 µmol g-1 h-1 with AQY (apparent quantum efficiency) at 420 nm of 3.14% and 17.71%. Forming a Schottky junction, the surface-modified Ni nanoparticles broaden the light absorption boundary and facilitate charge separation, which act as active sites, promoting O2 adsorption and reducing the formation energy of *OOH (reaction intermediate). This results in a substantial improvement in both H2O2 generation activity and selectivity. The Schottky junction of dual modulation strategy provides novel insights into the advancement of highly effective photocatalytic agents for the photosynthesis of H2O2.

Highly efficient charge transfer from small-sized cadmium sulfide nanosheets to large-scale nitrogen-doped carbon for visible-light dominated hydrogen evolution.

Slow charge transfer and carrier recombination are key issues in photocatalytic reactions. The current solution is to load small-sized cocatalysts onto large-sized photocatalysts. Here a new strategy is proposed. Small-sized photocatalysts of cadmium sulfide (CdS) nanosheets are grown onto large-sized cocatalysts of N-doped amorphous carbon (a-CN) to construct CdS @ a-CN photocatalysts. Photoluminescence spectra and transient photocurrent demonstrate that optimized CdS @ a-CN shows effective charge separation compared with CdS. The corresponding photocatalytic H2 yield of optimized CdS @ a-CN is âˆ¼244 µmol, which is 3.6 times higher than that of CdS. Besides, the hydrogen yield for CdS under visible-light irradiation is significantly improved from âˆ¼44 µmol to âˆ¼217 µmol for the optimized CdS @ a-CN. Our design strategy provides an effective way to construct photocatalytic systems with outstanding photocatalytic performance.

A Glass-Ceramic with Accelerated Surface Reconstruction toward the Efficient Oxygen Evolution Reaction.

The effective non-precious metal catalysts toward the oxygen evolution reaction (OER) are highly desirable for electrochemical water splitting. Herein, we prepare a novel glass-ceramic (Ni1.5 Sn@triMPO4 ) by embedding crystalline Ni1.5 Sn nanoparticles into amorphous trimetallic phosphate (triMPO4 ) matrix. This unique crystalline-amorphous nanostructure synergistically accelerates the surface reconstruction to active Ni(Fe)OOH, due to the low vacancy formation energy of Sn in glass-ceramic and high adsorption energy of PO4 3- at the VO sites. Compared to the control samples, this dual-phase glass-ceramic exhibits a remarkably lowered overpotential and boosted OER kinetics after surface reconstruction, rivaling most of state-of-the-art electrocatalysts. The residual PO4 3- and intrinsic VO sites induce redistribution of electron states, thus optimizing the adsorption of OH* and OOH* intermediates on metal oxyhydroxides and promoting the OER activity.

Investigations of EGFR configurations on tumor cell surface by high-resolution electron microscopy.

Epidermal growth factor receptor (EGFR) is an important target for tumor therapy in various tumors. The current understanding of EGFR conformations on the cell surface is based on X-ray structural data, molecular dynamic simulations, and fluorescence-localization imaging. Using scanning electron microscope (SEM) and transmission electron microscope (TEM) with the resolution at sub-nanometers, we successfully recognized individual molecules of EGFRs and their assembly details on the surface of triple-negative breast cancer (TNBC) upon one-to-one labeling by Au nanoparticles. Based on our results, we have proposed the possible configurations, structural models, and conformational transitions of EGFR oligomers. Our study shows that the high-resolution electron imaging is an invaluable tool to provide direct evidence of EGFR configuration on tumor cell surfaces, and may play a pivotal role in further understanding of EGFR-associated signaling and tumor therapy.

In†Situ Observation of Dynamic Galvanic Replacement Reactions in Twinned Metallic Nanowires by Liquid Cell Transmission Electron Microscopy.

Galvanic replacement is a versatile approach to prepare hollow nanostructures with controllable morphology and elemental composition. The primary issue is to identify its fundamental mechanism. In this study, in situ liquid cell transmission electron microscopy was employed to monitor the dynamic reaction process and to explore the mechanism of galvanic replacement. The detailed reaction process was revealed based on in situ experiments in which small Au particles first appeared around Ag nanowires; they coalesced, grew, and adhered to Ag nanowires. After that, small pits grew from the edge of Ag nanowires to form tubular structures, and then extended along the Ag nanowires to obtain hollowed structures. All of our experimental observations from the viewpoint of electron microscopy, combined with DFT calculations, contribute towards an in-depth understanding of the galvanic replacement reaction process and the design of new materials with hollow structures.