The poor cycling stability resulting from the large volume expansion caused by lithiation is a critical issue for Si‐based anodes. Herein, we report for the first time of a new yolk–shell structured high tap density composite made of a carbon‐coated rigid SiO2 outer shell to confine multiple Si NPs (yolks) and carbon nanotubes (CNTs) with embedded Fe2O3 nanoparticles (NPs). The high tap density achieved and superior conductivity can be attributed to the efficiently utilised inner void containing multiple Si yolks, Fe2O3 NPs, and CNTs Li+ storage materials, and the bridged spaces between the inner Si yolks and outer shell through a conductive CNTs “highway”. Half cells can achieve a high area capacity of 3.6 mAh cm−2 and 95 % reversible capacity retention after 450 cycles. The full cell constructed using a Li‐rich Li2V2O5 cathode can achieve a high reversible capacity of 260 mAh g−1 after 300 cycles.

Engineering the electronic structure of BiOCl through the creation of oxygen vacancies can be a good strategy to enhance the photooxidation activity of BiOCl.

We presented a new type II heterojunction photocatalyst with a strong built-in electric field aligned between the spatially well-defined redox sites to effectively suppress the charge recombination for efficient photocatalytic hydrogen generation via HI splitting. This brings the hydrogen generation performance of the perovskite-based photocatalysts to a new horizon with a champion STH efficiency of 1.09% and a record hydrogen generation activity of 13.6 mmol g À1 h À1 under visible light.

We investigate the nonlinear optical properties of BiOBr nanoflakes—a novel two-dimensional (2D) layered material from the bismuth oxyhalide family. We measure the nonlinear absorption and Kerr nonlinearity of BiOBr nanoflakes at both 800 nm and 1550 nm via the Z-Scan technique. We observe a large nonlinear absorption coefficient β ∼ 10−7 m/W as well as a large Kerr coefficient n2 ∼ 10−14 m2/W. We also observe strong dispersion in n2, with it reversing sign from negative to positive as the wavelength varies from 800 nm to 1550 nm. In addition, we characterize the thickness-dependence of the nonlinear optical properties of BiOBr nanoflakes, observing that both the magnitudes of β and n2 increase for very thin flakes. Finally, we integrate BiOBr nanoflakes onto silicon integrated waveguides and characterize the linear optical properties of the resulting hybrid integrated devices, with the measurements agreeing with calculated parameters using independent ellipsometry measurements. These results verify the strong potential of BiOBr as an advanced nonlinear optical material for high-performance hybrid integrated photonic devices.