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The etching of ZnO thin films using acetylacetone (Hacac) doses with long exposure times, followed by purging and subsequent exposure to O2 plasma, is studied in a hot-wall reactor using simultaneous in situ spectroscopic ellipsometry and quadrupole mass spectrometry. The static exposure step results in the efficient consumption of Hacac. For each etch cycle, the O2 plasma plays a crucial role in removing unreacted Hacac from the ZnO surface, priming the surface for subsequent Hacac etching. This is confirmed by the production of CO2 during the O2 plasma pulse. The temperature window for etching is established as 220–280 °C with a maximum etch per cycle (EPC) of 0.15 nm/cy. Under these conditions, the Hacac pulse is 2 s long with a 30 s static hold step followed by 5 s O2 plasma step at 300 W power. Statistical analyses of etch data at the granularity level of each cycle reveal the importance of the static hold step in determining EPC. Arrhenius behavior of etching during the hold step reveals a piecewise linear trend with a low temperature (120–200 °C) activation energy (Ea) of 202 meV and a high temperature (200–320 °C) Ea of 32 meV. It is shown that saturation behavior in EPC is pulse time and static hold time dependent. Shorter Hacac pulses (≤1 s) demonstrate saturation behavior for static hold times ∼30 s, longer pulses of Hacac (≥2 s) show no saturation in EPC with static hold times up to 75 s. 

In depth thermogravimetric analysis and direct comparison of commercial volatile molecular tungsten-based precursors for atomic layer deposition. 

A hierarchical heterogeneous palladium on nickel foam-based catalyst system was demonstrated for the selective hydrogenation of quinoline and quinoline derivatives under low H₂pressures, with green solvents (ethanol, ethanol water mixture). 

Self-sorting of two imine-based Cu(i) and Fe(ii) coordination complexes from a six-component reagent library has been achieved through solvent-free mechanochemistry. The reaction proceeds rapidly, yielding the thermodynamically favored products in less than 24 hours. The results point to the potential of mechanochemistry to achieve increasingly complex multi-metallic systems through one-pot protocols. 

In this contribution we demonstrate that metal–organic frameworks (MOFs) with suitable underlying topological structure are amenable for the preparation of MOF-based substitutional solid-solutions (SSS) that follow Vegard's law. 

Abstract Manufacturing custom three-dimensional (3D) carbon functional materials is of utmost importance for applications ranging from electronics and energy devices to medicine, and beyond. In lieu of viable eco-friendly synthesis pathways, conventional methods of carbon growth involve energy-intensive processes with inherent limitations of substrate compatibility. The yearning to produce complex structures, with ultra-high aspect ratios, further impedes the quest for eco-friendly and scalable paths toward 3D carbon-based materials patterning. Here, we demonstrate a facile process for carbon 3D printing at room temperature, using low-power visible light and a metal-free catalyst. Within seconds to minutes, this one-step photocatalytic growth yields rod-shaped microstructures with aspect ratios up to ~500 and diameters below 10 μm. The approach enables the rapid patterning of centimeter-size arrays of rods with tunable height and pitch, and of custom complex 3D structures. The patterned structures exhibit appealing luminescence properties and ohmic behavior, with great potential for optoelectronics and sensing applications, including those interfacing with biological systems. 

Understanding the origin of enhanced catalytic activity is critical to heterogeneous catalyst design. This is especially important for non-noble metal-based catalysts, notably metal oxides, which have recently emerged as viable candidates for numerous thermal catalytic processes. For thermal catalytic reduction/hydrogenation using metal oxide nanoparticles, enhanced catalytic performance is typically attributed to an increased surface area and the presence of oxygen vacancies. Concomitantly, the treatments that induce oxygen vacancies also impact other material properties, such as the microstrain, crystallinity, oxidation state, and particle shape. Herein, multivariate statistical analysis is used to disentangle the impact of material properties of CuO nanoparticles on catalytic rates for nitroaromatic and methylene blue reduction. The impact of the microstrain, shape, and Cu(0) atomic percent is demonstrated for these reactions; furthermore, a protocol for correlating material property parameters to catalytic efficiency is presented, and the importance of catalyst design for these broadly utilized probe reactions is highlighted.