The primary objective of this study is to investigate and develop a rapid and effective method for the immobilization of Sr in the event of a nuclear leakage incident. Coal gangue, an underutilized form of solid waste from the coal industry, can be used as a raw material for curing Sr due to its high content of silica–alumina oxides. In the present study, Sr was successfully solidified in cancrinite synthesized using a hydrothermal method with coal gangue as raw material. A stable cancrinite phase was formed at a relative alkali concentration of more than 6 M. When the Sr/Al(Si) ratio was <1/6, cancrinite was the only stable phase that varied with the hydrothermal temperature and time. When the Sr/Al(Si) ratio increased to 1/2, the cancrinite phase completely disappeared, and a new strontium feldspar phase (SrAl₂Si₂O₈) appeared. PCT leaching experiments showed that when Sr/Al(Si) < 1/6, the Sr leaching rate of Sr-cancrinite samples obtained by hydrothermal synthesis at 180 °C for 24 h was very low.

Tetradymite-structured chalcogenides, such as Bi₂Te₃ and Sb₂Te₃, are quasi-two-dimensional (2D) layered compounds, which are significant thermoelectric materials applied near room temperature. The intercalation of guest species in van der Waals (vdW) gap implemented for tunning properties has attracted much attention in recent years. We attempt to insert Ga atoms in the vdW gap between the Te layers in p-type Bi_0.3Sb_1.7Te₃ (BST) for further improving thermoelectrics. The vdW-related defects (including extrinsic interstitial and intrinsic defects) induced by Ga intercalation can not only modulate the carrier concentration but also enhance the texture, thereby yielding excellent electrical properties, which are reflected in the power factor PF ∼ 4.43 mW⋅m⁻¹⋅K⁻². Furthermore, the intercalation of Ga produces multi-scale lattice imperfections such as point defects, Te precipitations, and nanopores, realizing the low lattice thermal conductivity in BST-Ga samples. Ultimately, a peak zT ∼ 1.1 at 373 K is achieved in the BST-1% Ga sample and greatly improved by ∼ 22% compared to the pristine BST. The weak bonding of vdW interlayer interaction can boost the synergistic effect for advancing BST-based or other layered thermoelectrics.

In this paper, pyramidal notch array was pre-etched on P(100) silicon wafer using anisotropic wet chemical etching, then macro-pore/pillar array were successfully processed in the pyramidal notch array by an anodic electrochemical etching. The formation mechanism of macro-pore and pillar in pyramidal notch were investigated, it indicates that the silicon dissolution rate is proportional to electric field, while electric field is mainly concentrated on the tip, edges and corners of the pyramidal notch. Therefore, there is an etching rate difference between the notch corner and planar regions in the pyramid notch. The notch corners are preferentially etched at first, then a pore is formed in the notch. If the shape of the open window is truncated and the bottom size is large enough, four pores would initiate at the notch angels due to etching rate difference between the truncated pyramidal notch corner and notch center, consequently, a pillar is formed in the notch center.