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Two-dimensional silicon (Si) nanosheets are becoming increasingly exciting for photocatalytic applications. Their unique morphology and physiochemical properties make it attractive in heterojunction engineering. In this work, we report the construction of 2D H–Si/g-C3N4 hybrid as a heterojunction photocatalyst for solar photocatalytic hydrogen evolution. The exfoliated silicon nanosheets etched by hydrofluoric acid exhibit a hydrogen-terminated surface with an inverse charging state, which can thus be easily anchored onto g-C3N4 nanosheets by self-assembly. The optimized H–Si/g-C3N4 heterojunction photocatalyst with Pt as the cocatalyst achieved an improved photocatalytic hydrogen production rate which is about 2 times that of g-C3N4 nanosheets under simulated sunlight irradiation using methanol as the sacrificial agent. Density functional theory calculations revealed that the built-in electric field (BIEF) at the H–Si/g-C3N4 interface contributes to the spatial charge separation of the heterojunction. The BIEF leads to an S-scheme carrier transfer mechanism at the H–Si/g-C3N4 interface that benefits the carrier separation on g-C3N4 nanosheets, resulting in uniform deposition of the Pt cocatalyst at the heterojunction interface and improved photocatalytic performance. This work not only expands the application of silicon nanosheets by supporting the potential of 2D H–Si/g-C3N4 heterojunction in photocatalytic reactions but also provides valuable insights to the interface behavior of the H–Si/g-C3N4 heterostructure. [ABSTRACT FROM AUTHOR]

Abstract:Catalyst surface dynamics drive the generation of active species for electrocatalytic reactions. Yet, the understanding of dominant site formation and reaction mechanisms is limited. In this study, we thoroughly investigate the dynamic reconstruction of two‐dimensional defective Bi nanosheets from exfoliated Bi2Se3 nanosheets under electrochemical CO2 and nitrate (NO3−) reduction conditions. The ultrathin Bi2Se3 nanosheets obtained by NaBH4‐assisted cryo‐mediated liquid‐phase exfoliation are more easily reduced and reconstructed to Bi nanosheets with high‐density grain boundaries (GBs; GB‐rich Bi). The reconstructed GB‐rich Bi catalyst affords a remarkable yield rate of 4.6 mmol h−1 mgcat.−1 and Faradaic efficiency of 32 % for urea production at −0.40 V vs. RHE. Notably, this yield rate is 2 and 8.2 times higher than those of the low‐GB Bi and bulk Bi catalysts, respectively. Theoretical analysis demonstrates that the GB sites significantly reduce the *CO and *NH2 intermediate formation energy and C−N coupling energy barrier, enabling selective urea electrosynthesis on the GB‐rich Bi catalyst. This work will trigger further research into the structure‐activity interplay in dynamic processes using in situ techniques. [ABSTRACT FROM AUTHOR]

Introduction Attention-deficit/hyperactivity disorder (ADHD) is a heterogeneous disorder that affects 1 in 20 children and results in poor lifetime outcomes (1, 2). Males are approximately 3 to 4 times more [...], Attention-deficit/hyperactivity disorder (ADHD) is a prevalent psychiatric disorder in children. Although an imbalance of excitatory and inhibitory inputs has been proposed as contributing to this disorder, the mechanisms underlying this highly heterogeneous disease remain largely unknown. Here, we show that N-myc downstream-regulated gene 2 (NDRG2) deficiency is involved in the development of ADHD in both mice and humans. Ndrg2-knockout ([Ndrg2.sup.-/-]) mice exhibited ADHD-like symptoms characterized by attention deficits, hyperactivity, impulsivity, and impaired memory. Furthermore, interstitial glutamate levels and excitatory transmission were markedly increased in the brains of [Ndrg2.sup.-/-] mice due to reduced astroglial glutamate clearance. We developed an NDRG2 peptide that rescued astroglial glutamate clearance and reduced excitatory glutamate transmission in NDRG2-deficient astrocytes. Additionally, NDRG2 peptide treatment rescued ADHD-like hyperactivity in the [Ndrg2.sup.-/-] mice, while routine methylphenidate treatment had no effect on hyperactivity in these animals. Finally, children who were heterozygous for rs1998848, a SNP in NDRG2, had a higher risk of ADHD than children who were homozygous for rs1998848. Our results indicate that NDRG2 deficiency leads to ADHD phenotypes and that impaired astroglial glutamate clearance, a mechanism distinct from the well-established dopamine deficit hypothesis for ADHD, underlies the resultant behavioral abnormalities.

The poor conductivity and large volume swelling of transition-metal sulfides are still big challenges to overcome for high-performance energy storage. Herein, the flexibility of MOF precursors offers remarkable versatility in tailoring the chemical composition of NiCo sulfides with a highly desirable porous structure, and then dual-carbon-confined (Ni0.28Co0.72)1–xS nanoparticles are designed, in which an inner sulfur-doped porous carbon (SC) matrix (derived from the organic ligands of metal–organic frameworks (MOFs)) and an outer wrapped S-doped reduced graphene oxide (SG)-co-engineered (Ni0.28Co0.72)1–xS are constructed ((Ni0.28Co0.72)1–xS/SC/SG)) to enhance the rate capability and stability of Li+ storage. For the dual carbons, the inner SC can elastically realize the anti-aggregation of nanosized (Ni0.28Co0.72)1–xS and improve their conductivity, while the outer SG could further promote the reaction kinetics, stabilize the structure, and ensure the structural integrity. As expected, the optimized (Ni0.28Co0.72)1–xS/SC/0.7SG exhibits an outstanding rate capability of 640.1 mAh g–1 at 5.0 A g–1 and ultrahigh cycling stability of 134.7% at 1 A g–1 after 1000 cycles. The assembled lithium-ion capacitor (LIC) also shows a high energy density of 125.8 Wh kg–1 at the power density of 200 W kg–1, as well as excellent stability (98.8% after 6000 cycles). This work highlights the significance of dual-carbon engineering in enhancing the energy storage performance of active materials, and the fabricated nanosized (Ni0.28Co0.72)1–xS by dual-carbon engineering can be applied in high-performance electrochemical energy storage and beyond. [ABSTRACT FROM AUTHOR]