Luminescent defects in hexagonal boron nitride (h-BN) have recently emerged as a promising platform for non-classical light emission. On-chip solutions, however, require techniques for controllable in-situ manipulation of quantum light. Here, we demonstrate the dynamic spectral and temporal tuning of the optical emission from h-BN via moving acousto-mechanical modulation induced by stimulated phonons. When perturbed by the propagating acoustic phonon, the optically probed radiative h-BN defects are periodically strained and their sharp emission lines are modulated by the deformation potential coupling. This results in an acoustically driven spectral tuning within a 2.5-meV bandwidth. Our findings, supported by first-principles theoretical calculations, reveal exceptionally high elasto-optic coupling in h-BN of ~50 meV/%. Temporal control of the emitted photons is achieved by combining the acoustically mediated fine-spectral tuning with spectral detection filtering. This study opens the door to the use of sound for scalable integration of h-BN emitters in nanophotonic and quantum information technologies.

Very recently, it has been reported that mixed transition metal oxide (TMO)/MXene catalysts show improved performance over TMO only catalysts for the oxygen evolution reaction (OER). However, the reasoning behind this observation is unknown. In this work mixed Co(OH)₂/Ti₃C₂T_xwere prepared and characterized for the OER using ex situ and operando spectroscopy techniques in order to initiate the understanding of why mixed TMO/MXene materials show better performances compared to TMO only catalysts. This work shows that the improved electrocatalysis for the composite material compared to the TMO only catalyst is due to the presence of higher Co oxide oxidation states at lower OER overpotentials for the mixed TMO/MXene catalysts. Furthermore, the presence of the MXene allows for a more mechanically robust film during OER, making the film more stable. Finally, our results show that small amounts of MXene are more advantageous for the OER during long-term stability measurements, which is linked to the formation of TiO₂. The sensitivity of MXene oxidation ultimately limits TMO/MXene composites under alkaline OER conditions, meaning mass fractions must be carefully considered when designing such a catalyst to minimize the residual TiO₂formed during its lifetime.

Additive manufacturing strategies are gaining more importance in the context of lithium‐ion batteries. The rapid prototyping, reduced waste and complex 3D structures achievable are powerful and attractive tools that are out of the reach of current fabrication techniques. Additionally, thanks to the potential that these manufacturing techniques hold for the fabrication of micro‐energy storage devices, they are gaining increasing attention in the literature. Here, some of the more common additive manufacturing techniques are compared to standard methodologies by systematically evaluating their electrochemical performance and correlating it with the physical changes induced by the printing process. By using LTO/CNT‐based inks, it is observed that the inner arrangement of the conductive additive is significatively altered depending on the technique used and that this has an impact on the rate performance of the device. By using a model that links the capacity‐rate data to the physical properties of the batteries, it is possible to find the limiting factor on the printed electrodes and correlate it with the material arrangement that each technique produces.