SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3930-3
Methylammonium lead tribromide (MAPbBr3) single crystals (SCs) are promising for room-temperature gamma-ray and X-ray detection, but scaling their size often compromises crystal quality. Here, we report a strategic precursor stoichiometry engineering approach to grow inch-sized, high-quality MAPbBr3 SCs via a constant-temperature evaporation method. We show that constructing a robust electrical double layer through organic cation modulation effectively stabilizes the colloidal precursor. This is achieved by synergistically suppressing MA+ deprotonation while promoting MA+ adsorption as counterions on the [PbBrn]2−n complexes, which collectively strengthens interparticle repulsion and raises the nucleation barrier. This multifaceted approach yields MAPbBr3 SCs with lateral dimensions up to 2 inches and an exceptional X-ray diffraction rocking curve full width at half maximum (FWHM) of 0.0093° at the (002) face. Consequently, the SCs enable spectroscopic-grade gamma-ray detection, achieving energy resolutions (ER) of 8.4% for the 57Co source (122 keV) and 11.1% for the 137Cs source (662 keV), along with a high X-ray sensitivity of 1.65 × 10^4 μC Gy−1 cm−2. This work paves the way for the practical application of MAPbBr3 SCs in high-performance gamma-ray and X-ray detection.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3927-9
The mechanical properties of as-cast TiAl alloys are severely limited by their coarse as-cast microstructure. This study proposes a low-temperature pre-deformation heat treatment to refine the microstructure of an as-cast Ti-47Al-2Nb-2Cr alloy. The process involves pre-deformation below the eutectoid temperature followed by heat treatment in the α+γ phase field, yielding two distinct microstructures: duplex (DP) and nearly lamellar (NL). The average lamellar colony size was reduced to 5.3% and 20% of the as-cast size for DP and NL structures, respectively. Microstructural evolution analysis reveals that the decomposition of coarse lamellar colonies and the formation of fine grains are governed by γ recrystallization, γ→α phase transformation, and α recrystallization. Remnant colonies after deformation are completely eliminated by subsequent heat treatment, enhancing microstructural homogeneity and mechanical properties. The DP alloy exhibits an ultimate tensile strength (UTS) of 537 MPa and an elongation (EI) of 6.8% at 800°C, representing increases of 44.7% and 518.2% over the as-cast alloy, respectively. Analysis of crack propagation and deformation mechanisms indicates that grain refinement and lamellar structure refinement contribute to improved deformation ability. This work provides a viable pathway for optimizing as-cast TiAl alloys for high-temperature applications.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202509080
Plastic pollution poses a global environmental challenge, and developing efficient, low-cost pyrolysis catalysts is crucial for resource recovery from plastic waste. This study investigates ex-situ catalytic pyrolysis of low-density polyethylene (LDPE) over ZSM-5 (Si/Al = 25) modified with Zn and Fe at loadings of 5% and 10% via impregnation. Catalysts were characterized by XRD, FT-IR, XPS, SEM, TEM, and BET. TGA was used to assess thermal behavior, and catalytic pyrolysis experiments were conducted in a tube furnace at 450 °C, with product analysis by GC-MS. Results show that metal incorporation preserved the ZSM-5 framework while modifying acid site distribution and surface morphology, enhancing cracking and dehydrogenation. All modified catalysts increased light gasoline-range hydrocarbon yield and reduced heavy fractions compared to non-catalytic runs. Among them, 10% Zn/ZSM-5 exhibited the best performance, boosting light gasoline hydrocarbons to 74.77%, approximately three times that of the non-catalytic case, significantly improving oil quality. This study demonstrates the potential of low-cost metal-modified zeolites for efficient and economical plastic waste pyrolysis.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4070-2
A series of ~20 nm intermetallic Pd3Pb nanocubes with tunable surface Pb exposure were synthesized via a facile one-step solvothermal approach, providing an ideal system to investigate the way in which the surface configurations of Pb-rich (Pd3Pb/Pb), Pd-rich (Pd3Pb/Pd), and standard Pd3Pb nanocubes influence the CO2 reduction reaction (CO2RR) mainly through the ligand effect while excluding geometric influences. Electrochemical measurement results indicate that the Pd3Pb/Pb catalyst delivered outstanding C1+ selectivity, achieving a high Faradaic efficiency of 96.88% at −0.72 V (vs. RHE), significantly outperforming the Pd3Pb/Pd (39.86%) and standard Pd3Pb (81.75%) counterparts. In situ FTIR together with DFT calculations further elucidated that Pb incorporation can modulate the electronic structure of Pd via p-d hybridization, leading to the upshift of the d-band center. This will, in return, strengthen the intermediate adsorption ability and lower the energy barriers of the C1+ pathways while effectively suppressing the competing hydrogen evolution reaction. This work establishes a precise surface engineering paradigm of intermetallic nanocrystals for designing high-performance electrocatalysts.