Photocatalytic water splitting is a promising approach for sustainable green hydrogen production, but its practical deployment is severely hindered by two critical limitations: mandatory H 2 /O 2 separation and the requirement for high-pressure hydrogen storage facilities. To address this long-standing bottleneck, a Ru-TiO 2 /Ti 2 C heterostructured photocatalyst is fabricated via a combined hydrothermal and ball-milling route. Operando spectroscopy and DFT calculations verify a cascade charge and hydrogen transfer pathway: photogenerated electrons migrate from TiO 2 to metallic Ru sites to drive water dissociation into surface H* intermediates, which then spillover onto the Ti 2 C substrate. Owing to the strong atomic hydrogen affinity of Ti 2 C, accumulated H* is immobilized in the Ti 2 C lattice via Ti-H covalent bonds, achieving in-situ atmospheric-pressure hydrogen storage. The optimized composite exhibits an in-situ hydrogen storage capacity of 2.1 wt% at ambient temperature and pressure, with a markedly reduced desorption temperature of 216°C and excellent cycling durability. This work establishes an integrated paradigm of photocatalytic water splitting and low-pressure hydrogen storage, offering a feasible strategy to resolve the inherent H 2 /O 2 separation dilemma and advance the practical application of solar-driven hydrogen production.
The 0.55LiBH 4 -0.45Mg(BH 4 ) 2 (LMBH) eutectic composite is promising for solid-state hydrogen storage, as it exhibits a high hydrogen capacity and a very low initial dehydrogenation temperature. However, its main hydrogen release steps still require higher temperatures. In the present study, few-layer Ti 2 C has been synthesized and utilized as catalysts in the LMBH. Compositing LMBH with varying amounts of Ti 2 C (10, 20, 30, and 40 wt%) results in low initial dehydrogenation temperatures (164–110 °C), fast desorption rates and high hydrogen capacities (7.5–10.5 wt%) at a low temperature of 260 °C. The LMBH-30Ti 2 C composite yields 6.5 wt% H 2 even at as low as 200 °C. Additionally, the LMBH-30Ti 2 C composite could reversibly store 3.5 wt% H 2 during the second to fourth dehydrogenation cycles without degradation. The outstanding hydrogen storage performance could be attributed to decomposition driven by reactions between high-valence Ti ions and LMBH, the in-situ formation of the active metal Ti catalyst, and the prevention of aggregation in the Ti 2 C-doped LMBH.
Yefeng Feng,Peiyao Chen,Bingshuang Mao,Maolin Bo,Qihuang Deng
Ultrahigh dielectric constant is obtained in polymer/MXene composites due to percolation . However, huge dielectric loss is triggered owing to high leakage current . In this work, hybrid filler consisting of Ti 2 C MXene and ZrO 2 was prepared for coordinating high dielectric constant and low dielectric loss in composites. Instead of Ti 2 C percolation, Ti 2 C/ZrO 2 interface effect mildly increased dielectric constant. Ultrahigh insulation and large aspect ratio of ZrO 2 fibers significantly reduced dielectric loss. Binary polymer/Ti 2 C and ternary polymer/Ti 2 C-ZrO 2 composites were fabricated, and better overall electric traits in ternary system were found. Ti 2 C/ZrO 2 interface effect was studied using density functional theory (DFT) calculations. Ternary composite with 12 wt% filler exhibited high dielectric constant of ~40, low dielectric loss of ~0.09 at 100 Hz and high breakdown strength of ~155 MV m −1 . This work might impulse fabrication of MXene-based hybrid fillers for dielectrics.
危险品化学品经营许可证（带存储）