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The development of a high current density with high energy conversion efficiency electrocatalyst is vital for large-scale industrial application of alkaline water splitting, particularly seawater splitting. Herein, we design a self-supporting Co3(PO4)2-MoO3–x/CoMoO4/NF superaerophobic electrode with a three-dimensional structure for high-performance hydrogen evolution reaction (HER) by a reasonable devise of possible “Co-O-Mo hybridization” on the interface. The “Co-O-Mo hybridization” interfaces induce charge transfer and generation of fresh oxygen vacancy active sites. Consequently, the unique heterostructures greatly facilitate the dissociation process of H2O molecules and enable efficient hydrogen spillover, leading to excellent HER performance with ultralow overpotentials (76 and 130 mV at 100 and 500 mA cm–2) and long-term durability of 100 h in an alkaline electrolyte. Theoretical calculations reveal that the Co3(PO4)2-MoO3–x/CoMoO4/NF promotes the adsorption/dissociation process of H2O molecules to play a crucial role in improving the stability and activity of HER. Our results exhibit that the HER activity of non-noble metal electrocatalysts can be greatly enhanced by rational interfacial chemical bonding to modulate the heterostructures.

Shield tunnels built in soft soil are prone to settlement, which is often accompanied by convergence deformation, further resulting in a series of damages to the tunnel structure and compromise its safety in service. This paper presents an engineering case on the settlement development and internal drilling grouting remediation of a tunnel section in Shaoxing Metro Line 1, where the inner diameter and thickness of the tunnel linings are increased to be 5.9 m and 400 mm simultaneously. The tunnel settlement arises from a comprehensive analysis of several contributing factors, encompassing ground disturbances such as pile driving, pile extraction, backfilling of pile holes, road structure construction, and road traffic. A grouting remediation plan is thoughtfully designed, including a careful assessment on the necessity for a temporary steel support system which is based on a full-scale three-ring test of the tunnel structure. The deformation of the tunnel during settlement and grouting processes is thoroughly analyzed to investigate the deformation resistance capacity exhibited by the thickened larger-diameter tunnel. The case study and experimental results demonstrate that tunnel structures with an increased diameter and thickness have better deformation resistance than conventional metro tunnels in soft soil layers. The analysis of this study can provide a reference for tunnel structures optimization and similar grouting remediation projects in shield tunnels.

Passivating defects to suppress recombination is a valid tactic to improve the performance of third-generation perovskite-based solar cells. Pb0is the primary defect in Pb-based perovskites. Here, tris(pentafluorophenyl)borane is inserted between the perovskite and spiro-OMeTAD layer in SnO2-based planar perovskite solar cells. The incorporation of tris(pentafluorophenyl)borane can effectively passivate Pb0defects, decreasing recombination at the surface of the perovskite film. Additionally, the modification with tris(pentafluorophenyl)borane decreases the grain boundaries quantity in the perovskite film, enhancing the transportation capability of carriers. The resulting perovskite solar cell gets a high efficiency of 21.42%. While the reference device without tris(pentafluorophenyl)borane treatment acquires an efficiency of 19.07%. More importantly, the stability tests manifest that incorporating tris(pentafluorophenyl)borane in perovskite solar cells is conducive to the stability of the device.

Two dimensional excitonic devices are of great potential to overcome the dilemma of response time and integration in current generation of electron or/and photon based systems. The ultrashort diffusion length of exciton arising from ultrafast relaxation and low carrier mobility greatly discounts the performance of excitonic devices. Phonon scattering and exciton localization are crucial to understand the modulation of exciton flux in two dimensional disorder energy landscape, which still remain elusive. Here, we report an optimized scheme for exciton diffusion and relaxation dominated by phonon scattering and disorder potentials in WSe2monolayers. The effective diffusion coefficient is enhanced by > 200% at 280 K. The excitons tend to be localized by disorder potentials accompanied by the steadily weakening of phonon scattering when temperature drops to 260 K, and the onset of exciton localization brings forward as decreasing temperature. These findings identify that phonon scattering and disorder potentials are of great importance for long-range exciton diffusion and thermal management in exciton based systems, and lay a firm foundation for the development of functional excitonic devices.