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Tailoring the properties of microfabricated ceramics through doping can unlock new avenues for the additive manufacturing (AM) of advanced 3D architectures. The first step to achieving optical functionality is to control material morphology, crystallinity, and defects associated with the composition of the produced AM architecture and dopants. For this purpose, AM of zinc‐doped zirconia (ZrO2:Zn) 3D microarchitectures is proposed using two‐photon lithography and tailor‐made resin. It is found that Zn doping modulates ZrO2:Zn architecture crystallinity and optical properties. The modification of optical properties through Zn doping is confirmed by micro‐photoluminescence, where higher energy photon emission is observed due to the promotion of oxygen vacancies and surface defects. It is also shown that Zn 2.5% and 5 wt% stabilizes the monoclinic ZrO2 at a lower temperature than in the case of undoped ZrO2. Furthermore, there is evidence that Zn tends to form ZnO wurtzite, which is later sublimated. The findings provide a promising route to understand the role of defects ZrO2:Zn optically upon annealing. [ABSTRACT FROM AUTHOR]

Locally controlling the position of electrodes in 3D can open new avenues to collect electrochemical signals in complex sensing environments. Implementing such electrodes via an electrical network requires advanced fabrication approaches. This work uses corner lithography and Pt ALD to produce electrochemical 3D electrodes. The approach allows the fabrication of (sub)micrometer size Pt octahedra electrodes spatially supported over 3D fractal‐like structures. As a proof of concept, electrochemical sensing of ferrocyanide in biofouling environments, e.g., bovine serum albumin (BSA) and Pseudomonas aeruginosa (P. aeruginosa), is assessed. Differences between before and after BSA addition show a reduction in the active electrode surface area (ΔAeff) ≈49% ± 7% for the flat electrode. In comparison, a ΔAeff reduction of 25% ± 2% for the 3D electrode has been found. The results are accompanied by a 24% ± 16% decrease in peak current for the flat Pt substrate and a 14% ± 5% decrease in peak current for the 3D electrode 24 h after adding BSA. In the case of P. aeruginosa, the 3D electrode retains electrochemical signals, while the flat electrode does not. The results demonstrate that the 3D Pt electrodes are more stable than their flat counterparts under biofouling conditions. [ABSTRACT FROM AUTHOR]

Vanadium redox flow batteries (VRFBs) are appealing large‐scale energy storage systems due to their unique properties of independent energy/power design. The VRFBs stack design is crucial for technology deployment in power applications. Besides the design, the stack suffers from high voltage losses caused by the electrodes. The introduction of active sites into the electrode to facilitate the reaction kinetic is crucial in boosting the power rate of the VRFBs. Here, an O‐rich layer has been applied onto structured graphite felt (GF) by depositing WO3 to increase the oxygen species content. The oxygen species are the active site during the positive reaction (VO2+/VO2+) in VRFB. The increased electrocatalytic activity is demonstrated by the monoclinic (m)‐WO3/GF electrode that minimizes the voltage losses, yielding excellent performance results in terms of power density output and limiting current density (556 mWcm−2@800 mAcm−2). The results confirm that the m‐WO3/GF electrode is a promising electrode for high‐power in VRFBs, overcoming the performance‐limiting issues in a positive half‐reaction. [ABSTRACT FROM AUTHOR]

Implementation of more refined structures at the nano to microscale is expected to advance applications in optics and photonics. This work presents the additive manufacturing of 3D luminescent microarchitectures emitting light in the visible range. A tailor‐made organo‐metallic resin suitable for two‐photon lithography is developed, which upon thermal treatment in an oxygen‐rich atmosphere allows the creation of silicon‐free tetragonal (t‐) and monoclinic (m‐) ZrO2. The approach is unique because the tailor‐made Zr‐resin is different from what is achieved in other reported approaches based on sol−gel resins. The Zr‐resin is compatible with the Eu‐rich dopant, a luminescent activator, which enables to tune the optical properties of the ZrO2 structures upon annealing. The emission characteristics of the Eu‐doped ZrO2 microstructures are investigated in detail with cathodoluminescence and compared with the intrinsic optical properties of the ZrO2. The hosted Eu has an orange−red emission showcased using fluorescence microscopy. The presented structuring technology provides a new platform for the future development of 3D luminescent devices. [ABSTRACT FROM AUTHOR]

The development of cheap and robust heterogeneous catalysts for the Meerwein‐Ponndorf‐Verley (MPV) reduction is desirable due to the difficulties in product isolation and catalyst recovery associated with the traditional use of homogeneous catalysts for MPV. Herein, we show that microwave heated γ‐Al2O3 can be used for the reduction of aldehydes to alcohols. The reaction is efficient and has a broad substrates scope (19 entries). The products can be isolated by simple filtration, and the catalyst can be regenerated. With the use of microwave heating, we can direct the heating to the catalyst rather than to the whole reaction medium. Furthermore, DFT was used to study the reaction mechanism, and we can conclude that a dual‐site mechanism is operative where the aldehyde and 2‐propoxide are situated on two adjacent Al sites during the reduction. Additionally, volcano plots were used to rationalize the reactivity of Al2O3 in comparison to other metal oxides. [ABSTRACT FROM AUTHOR]

Additive manufacturing, europium, luminescence, two-photon lithography, zirconia Keywords: additive manufacturing; europium; luminescence; two-photon lithography; zirconia EN additive manufacturing europium luminescence two-photon lithography zirconia 1 1 1 06/22/22 20220620 NES 220620 In article number 2102758, Jedrzej Winczewski, Arturo Susarrey Arce, Han Gardeniers and co-workers present additively-manufactured 3D luminescent microstructures emitting light in the visible range. The 3D europium-doped zirconia (ZrO SB 2 sb :Eu SP 3+ sp ) architectures are fabricated via two-photon lithography using custom-made photoresin. [Extracted from the article]