The reduction of surface "native" oxides from GaAs substrates following reactions with trimethylaluminum ͑TMA͒ precursor is studied using medium energy ion scattering spectroscopy ͑MEIS͒ and x-ray photoelectron spectroscopy ͑XPS͒. MEIS measurements after one single TMA pulse show that ϳ65% of the native oxide is reduced, confirmed by XPS measurement, and a 5 Å thick oxygen-rich aluminum oxide layer is formed. This reduction occurs upon TMA exposure to as-received GaAs wafers.

Using air as the oxidant instead of the traditionally employed persulfates, the smaller and more uniform Pd nanoparticles (around 2 nm) supported on polyaniline (Pd@PANI) can be easily fabricated by the oxidation-polymerization of aniline with PdCl2. This material is an efficient and environmentally friendly catalyst for Heck reactions due to its recyclability, low loading, and ligand-free and mild reaction conditions. It was even tolerant to sulfur-containing substrates. This work reports the Pd@PANI-catalyzed Heck reactions with very wide substrate scopes, and discloses the catalytic mechanisms based on experimental findings and results of catalyst analysis and characterization.

In addition to the significance of photocatalytic hydrogen evolution, the utilization of the in situ generated H/D (deuterium) active species from water splitting for artificial photosynthesis of high value‐added chemicals is very attractive and promising. Herein, photocatalytic water splitting technology is utilized to generate D‐active species (i.e., Dad) that can be stabilized on anchored 2nd metal catalyst and are readily for tandem controllable deuterations of carbon–carbon multibonds to produce high value‐added D‐labeled chemicals/pharmaceuticals. A highly crystalline K cations intercalated polymeric carbon nitride (KPCN), rationally designed, and fabricated by a solid‐template induced growth, is served as an ultraefficient photocatalyst, which shows a greater than 18‐fold enhancement in the photocatalytic hydrogen evolution over the bulk PCN. The photocatalytic in situ generated D‐species by superior KPCN are utilized for selective deuteration of a variety of alkenes and alkynes by anchored 2nd catalyst, Pd nanoparticles, to produce the corresponding D‐labeled chemicals and pharmaceuticals with high yields and D‐incorporation. This work highlights the great potential of developing photocatalytic water splitting technology for artificial photosynthesis of value‐added chemicals instead of H2 evolution.

Hexavalent Se? Yes! Selenium on polymers exhibits quite different properties compared to that in small molecules. Hexavalent Se, rare in organoselenium chemistry, was found to be the major species on polymers. The high-valent Se species on recyclable polymer resins could quickly catalyze the oxidation reaction of cyclohexene with H 2 O 2 in water to produce industrially important intermediate trans-1,2cyclohexanediol in almost quantitative yield. In the catalytic cycle, high valent Se species were reduced to divalent Se, a highly activated species that could be re-oxidized by air so that no excess H 2 O 2 was required for the reaction. The results were superior to those of reactions catalyzed by small molecules, for which excess H 2 O 2 , long reaction time or expensive CF 3 -activated catalysts and environmentally unfriendly MeCN solvent were required.