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Ambient pressure XPS is a powerful technique capable of performing measurements with samples kept at mbar pressure. The filled gas, also X‐ray ionized, provides electrons to neutralize positive charges built up on insulating samples. However, this convenient neutralization scheme does not solve the charging problem completely. In this study, the effectiveness of how the electrons generated from conducting mechanical parts mounted in the immediate front of insulating samples neutralize positive charges on the samples during XPS measurements is tested. The mechanical parts range from fine gold mesh, holey carbon film to graphene monolayer, and measured insulating samples are polished sapphire and rough pellets of CaCO3 powder. All these mechanical add‐ons reduce the charging to different degrees at the expense of sample signal. Amazingly, the graphene monolayer is found to effect perfect charge neutralization for both smooth sapphire and rough CaCO3 pellet, evidenced by realistic spectral profile and binding energy values. The finding that an untreated CaCO3 pellet is often terminated with Ca(OH)(HCO3) is consistent with earlier reports. It is speculated that a likely conformal covering with graphene on the sample with rough morphology holds the key to its superb performance in charge compensation. [ABSTRACT FROM AUTHOR]

Imitating the natural photosynthesis to synthesize hydrocarbon fuels represents a viable strategy for solar-to-chemical energy conversion, where utilizing low-energy photons, especially near-infrared photons, has been the ultimate yet challenging aim to further improving conversion efficiency. Plasmonic metals have proven their ability in absorbing low-energy photons, however, it remains an obstacle in effectively coupling this energy into reactant molecules. Here we report the broadband plasmon-induced CO2 reduction reaction with water, which achieves a CH4 production rate of 0.55 mmol g−1 h−1 with 100% selectivity to hydrocarbon products under 400 mW cm−2 full-spectrum light illumination and an apparent quantum efficiency of 0.38% at 800 nm illumination. We find that the enhanced local electric field plays an irreplaceable role in efficient multiphoton absorption and selective energy transfer for such an excellent light-driven catalytic performance. This work paves the way to the technique for low-energy photon utilization. Changes in Polycomb repression during interphase transition modulate the ability of pluripotent cells to enter cell differentiation. [ABSTRACT FROM AUTHOR]

Abstract: Synchrotron XPS and Cu [L.sub.2,3]-edge NEXAFS spectroscopic data for a natural tetrahedrite surface prepared by fracture under UHV were in accord with the composition of the mineral and its [...]

Copper (Cu) compounds are used in a case study to determine the effect of thermal treatment to fix soil contaminants. The leaching ability of Cu is graphed at temperatures ranging from 105 degrees Celsius up to 900 degrees Celsius.

Zinc metal is considered a promising anode material for aqueous zinc ion batteries. However, it suffers from dendrite growth, corrosion, and low coulombic efficiency (CE) during plating/stripping. Herein, a concentrated hybrid (4 m Zn(CF3SO3)2 + 2 m LiClO4) aqueous electrolyte (CHAE) to overcome the challenges facing the Zn anode is reported. The developed electrolyte achieves dendrite‐free Zn plating/stripping and obtains an excellent CE of ≈100%, surpassing the previously reported values. The combination of synchrotron‐based in operando transmission X‐ray microscopy, X‐ray diffraction, and ex situ X‐ray photoelectron spectroscopy analyses indicate that the denser, anion‐derived passivation layer formed using the CHAE facilitates homogeneous current distribution and better prevents freshly deposited Zn from directly contacting the electrolyte than the looser, solvent‐derived layers formed from a dilute hybrid aqueous electrolyte (DHAE). The beneficial effects of the CHAE on the compact, dense, and stable salt‐anion‐derived passivation layer can be attributed to its unique solvation structure, which suppresses the water‐related side reactions and widens the electrochemical potential window. In the hybrid Zn||LiFePO4 configuration, the CHAE‐based cell delivered a stable performance of CE >99% and capacity retention >90% after 285 cycles. In contrast, the DHAE‐based cell exhibits capacity retention of <65% after 170 cycles. [ABSTRACT FROM AUTHOR]