The notorious shuttling behaviors and sluggish conversion kinetics of the intermediate lithium polysulfides (LPS) are hindering the practical application of lithium sulfur (Li−S) batteries. Herein, an ultrafine, amorphous, and oxygendeficient niobium pentoxide nanocluster embedded in microporous carbon nanospheres (A-Nb 2 O 5−x @MCS) was developed as a multifunctional sulfur immobilizer and promoter toward superior shuttle inhibition and conversion catalyzation of LPS. The A-Nb 2 O 5−x nanocluster implanted framework uniformizes sulfur distribution, exposes vast active interfaces, and offers a reduced ion/electron transportation pathway for expedited redox reaction. Moreover, the low crystallinity feature of A-Nb 2 O 5−x manipulates the LPS chemical affinity, while the defect chemistry enhances the intrinsic conductivity and catalytic activity for rapid electrochemical conversions. Attributed to these superiorities, A-Nb 2 O 5−x @MCS delivers good Li−S battery performances, that is, high areal capacity of 6.62 mAh cm −2 under high sulfur loading and low electrolyte/sulfur ratio, superb rate capability, and cyclability over 1200 cycles with an ultralow capacity fading rate of 0.024% per cycle. This work provides a synergistic regulation on crystallinity and oxygen deficiency toward rapid and durable sulfur electrochemistry, holding a great promise in developing practically viable Li−S batteries and enlightening material engineering in related energy storage and conversion areas.

The electrochemical reduction of carbon monoxide is a promising approach for the renewable production of carbon-based fuels and chemicals. Copper shows activity toward multi-carbon products from CO reduction, with reaction selectivity favoring two-carbon products; however, efficient conversion of CO to higher carbon products such as n-propanol, a liquid fuel, has yet to be achieved. We hypothesize that copper adparticles, possessing a high density of under-coordinated atoms, could serve as preferential sites for n-propanol formation. Density functional theory calculations suggest that copper adparticles increase CO binding energy and stabilize two-carbon intermediates, facilitating coupling between adsorbed *CO and two-carbon intermediates to form three-carbon products. We form adparticle-covered catalysts in-situ by mediating catalyst growth with strong CO chemisorption. The new catalysts exhibit an n-propanol Faradaic efficiency of 23% from CO reduction at an n-propanol partial current density of 11 mA cm−2.

Photoelectrochemical water splitting is a clean and environmentally friendly method for solar hydrogen generation. Its practical application, however, has been limited by the poor stability of semiconductor photoelectrodes. In this work, we demonstrate the use of GaN nanostructures as a multifunctional protection layer for an otherwise unstable, low-performance photocathode. The direct integration of GaN nanostructures on n-p Si wafer not only protects Si surface from corrosion but also significantly reduces the charge carrier transfer resistance at the semiconductor/liquid junction, leading to long-term stability (>100 h) at a large current density (>35 mA/cm) under 1 sun illumination. The measured applied bias photon-to-current efficiency of 10.5% is among the highest values ever reported for a Si photocathode. Given that both Si and GaN are already widely produced in industry, our studies offer a viable path for achieving high-efficiency and highly stable semiconductor photoelectrodes for solar water splitting with proven manufacturability and scalability.

Here, we synthesized a series of α-MnO2 samples with differing K+ content but similar physical properties allowing direct study of the role of tunnel K+ on the electrochemistry of α-MnO2 cathodes.