Titanium alloys are unsuitable implants for patients with low bone quality due to their high moduli and bioinertness. In this study, porous boronized Ti6Al4V/fluorohydroxyapatite (FHA) composites are synthesized via microwave sintering of mixed Ti6Al4V, FHA and TiB2 powders at 1050 °C for 30 min, with 0–10 wt% urea as a space holder material. It is shown that increasing urea addition leads to higher porosity, promoting microwave penetration and microwave “lens effect”, which improves boronization and restrains degradation of mechanical properties of the composites caused by the increased porosity. With the urea addition of 0–3 wt%, the compressive strength and modulus decrease from 380.3 MPa and 14.5 GPa to 134.4 MPa and 3.26 GPa, respectively, while the Vickers microhardness declines from 360.3 to 300.0 HV. The increased exposure of FHA improves chemical and biological properties of the composite, with water contact angle decreased by nearly half and osteogenesis increased by sixfold. By adding more urea, the microhardness decreases evidently, with poorer wettability and biocompatibility due to looser structure and FHA decomposition. By adding 3 wt% urea, the composite achieves an optimal balance between ultralow modulus and enhanced bioactivity, making it ideal for rapid osseointegration in patients with poor bone conditions.

Moiré structures have gained attention for their ability to regulate material properties and drive phenomena such as superconductivity, topological effects, and the quantum Hall effect. This tunability also extends to Moiré ferroelectricity, which is essential for high‐performance, multistate electronic devices. However, most studies focus on few‐layer twisted materials from mechanical exfoliation. Although chemical vapor deposition (CVD) theoretically enables the direct growth of twisted multilayer materials with sliding Moiré ferroelectricity, this has yet to be achieved. The characteristics of van der Waals‐layered SnSe2, such as multiphase and broad bandgap, make it well suited for the direct growth of multilayer structures. Herein, multilayer Moiré‐twisted SnSe2 is synthesized using a non‐steady‐state CVD method. Layered and screw twists lead to Moiré structures, inducing ferroelectricity. Increasing the number of twists and layers enhances ferroelectric properties and signal feedback. These devices exhibit clear hysteresis and multistate ferroelectric performance under varying voltage drives.

The Cu compensatory doping of ZnO nanowires is of great interest to face the challenge arising from the detrimental screening of the piezoelectric potential generated under mechanical solicitations. However, the incorporation processes of Cu into ZnO nanowires are largely unknown. Here, they are investigated locally by combining mass spectrometry and optical spectroscopy with X‐Ray linear dichroism using synchrotron radiation. By varying the Cu(NO3)2/Zn(NO3)2 concentration ratio from 0 to 10% in a chemical bath kept at high pH, it is shown that the amount of Cu incorporated into ZnO nanowires varies from around 4.5 × 1016 to 3.6 × 1018 at cm−3. However, only 15% of the incorporated Cu forms CuZn‐related defects, while the remaining Cu lies on the surfaces of ZnO nanowires. Importantly, thermal annealing under O2 atmosphere is found to electrically activate the incorporated Cu, resulting in the formation of CuZn‐related defect complexes involving nearby VZn, the structured green emission band with a strong phonon coupling, and the increase in the electrical resistivity. These findings shed light on the local environment of Cu incorporated into ZnO nanowires and the required conditions for electrically activating the compensatory doping, as an important outcome for enhanced piezoelectric nanogenerators and stress/strain sensors.

Carbon dots (CDs) have attracted much attention for applications in photonics and optoelectronics because of their high emission efficiency and ease of synthesis. Although studies in solution are well established, solid‐state applications are less common because of optical quenching phenomena that critically affect CDs. Herein, the synthesis of amorphous CDs from citric acid, operating as hosts of dye molecules, and their incorporation into organic–inorganic silica matrices through a fast photo‐induced polymerization process are reported. The photocurable sol composition allows easy dispersion of nanometer‐sized scattering centers, such as titania or gold nanoparticles (NPs), which have been incorporated, along with CDs, into nanocomposites. The combination of high‐brightness CDs and nanoscatterers in the hybrid matrices allows for achieving and investigating the random lasing processes occurring in the orange‐red range of the visible spectrum. In situ‐grown gold NPs contribute to a significant improvement in solid‐state lasing, enabling an emission as narrow as 5 nm and a laser threshold as low as 0.3 mJ pulse−1. The present approach reveals the technological and scientific potential of CDs when embedded in solid‐state disordered active media.

New organic nonlinear optical crystals with a broad range free from strong molecular phonon vibrations have been developed for dimple‐free THz wave generation. The newly designed 7‐fluoro‐2‐(4‐hydroxy‐3‐methylstyryl)‐1‐methylquinolin‐1‐ium (OM7FQ) crystals exhibiting an optimal order parameter feature a unique orthogonal cation–anion dipole coupling, in contrast to the parallel cation–anion dipole coupling found in benchmark organic crystals. The introduction of a fluoro substituent on the cationic electron acceptor, compared to nonfluorinated analogs, results in the additional formation of stronger cation–anion and cation–cation interactions, leading to increased crystal density and reduced void volume. OM7FQ single crystals exhibit a broad phonon‐free range from 0.9 to 2.3 THz, defined by an absorption coefficient ≤15 mm−1. This leads to efficient, dimple‐free THz wave generation with a dimple‐free flat spectral band spanning 0.5–2.7 THz when pumped at the technically significant wavelength of 800 nm. Additionally, OM7FQ crystals produce THz electric fields 3.6 times higher than analogous nonfluorinated benchmark crystals with parallel cation–anion dipole coupling. The application of OM7FQ crystals in broadband THz spectroscopy has been successfully demonstrated for sensing biologically important lactose in commercial infant formulas.

The surface of carbon quantum dots (CDs) is rich in functionalities, which could be selectively post‐derivatized to obtain smart materials for various advanced applications. In this context, the development of a robust synthesis processes for CD formation is a considerable challenge to guarantee the reproducibility of the properties and functionalities on their surface for successful post‐derivatization. Thus, understanding the formation mechanism of CDs at the molecular level and its correlations with the reaction parameters is of paramount importance. Herein, we describe how two selected purification strategies and the reaction parameters influence the properties of CDs obtained through the hydrothermal method. We adopted a simplified approach employing small molecules that can be extracted from biomass/biowaste to develop a sustainable and scalable synthetic strategy for industrial applications. First, we studied the influence of the reaction parameters on the CD morphological, structural, and chemical properties. Then, we show how the reaction parameters, the temperature in particular, influence the formation of graphitic nitrogen oxide centers in CD honeycomb structure and their role in determining CDs color and stability. Finally, we concluded that low reaction temperatures cause an incomplete CD nucleation process while higher ones lead to more stable CDs, with reproducible properties and surface functionalities.

In electrocatalytic carbon dioxide reduction (CO2RR), indium (In)‐based catalysts with low toxicity and environmental benefits are renowned for their specific high selectivity for formic acid and intrinsic inertia for the competing hydrogen evolution reaction. However, recent studies have reported various products over In‐based catalysts showing comparable or even higher selectivity for carbon monoxide (CO) than for formic acid (HCOOH), puzzling the reaction pathway for CO2 reduction. This article presents a comprehensive review of recent studies on electrocatalytic CO2RR over In‐based catalysts highlighting the formation pathway of specific products. First, the mechanism of electrocatalytic CO2RR with the multiple reaction pathways is concluded considering the relationship between reaction intermediates and selectivity. Furthermore, the regulation strategies for multiple product formation are summarized, including crystalline phase engineering, alloying, nanostructuring, and structural modulation of In single atom, where the effect of key intermediates (*COOH, *OOCH, and *OCHO) on product generation is systematically discussed to achieve high selectivity. Finally, the intrinsic regulation mechanisms of these strategies are analyzed and the challenges and opportunities for the development of next‐generation In‐based catalysts are proposed.

Amide bond formation processes are of paramount relevance for a broad spectrum of applications. Conventional amidation protocols typically rely on drastic reaction conditions and the use/disposal of large amounts of chemicals. These limitations may be bypassed by heterogeneously catalyzed amidation at dry conditions. However, progress is hindered because the mechanisms of these processes are largely unexplored. By using ab initio metadynamics, a concerted one‐step mechanism is proposed for the solvent‐free condensation of methylamine and formic acid on TiO2(101)‐anatase, leading to methylformamide with concomitant release of molecular water. The activation barrier—14.3 kcal mol−1—is in line with the mild conditions experimentally adopted in amide bond syntheses on TiO2 nanoparticles. The mechanism disclosed herein reveals the key role of Ti4+ sites located on stoichiometric (101) anatase surfaces in promoting amide‐bond formation at the TiO2/vapor interface. The acid strength of the adsorbed HCOOH molecules may be tuned by the HCOOH surface coverage, thus influencing the outcome of the amidation reaction. These molecular‐level insights may foster further endeavors to improve/upscale TiO2‐catalyzed amide syntheses at dry conditions, while raising the interest toward amidation processes at the surface/vapor interface promoted by economically and environmentally sustainable metal oxide nanomaterials.