We report a synthetic route to achieving nanoscale heterostructures consisting of a metal core and monocrystalline semiconductor shell with substantial lattice mismatches between them, which cannot be obtained by conventional epitaxial techniques. By controlling soft acid-base coordination reactions between molecular complexes and colloidal nanostructures, we show that chemical thermodynamics can drive nanoscale monocrystalline growth of the semiconductor shell with a lattice structure incommensurate with that of the core. More complex hybrid core-shell structures with azimuthal and radial nanotailoring of structures and compositions of the monocrystalline semiconductor shell are also demonstrated.

Monodisperse nanospheres and spherical structures derived from them, such as core-shell or hollow nanospheres, have become a new study focus because their potential applications in optics, electrics, catalysis, sensors, and so forth. [1][2][3][4] Many researchers are working on the preparation of new monodisperse nanospheres and their functional transformation. [5][6][7][8][9][10][11][12][13][14] The traditional monodisperse micro-or nanospheres are amorphous silica and polymer colloids which were prepared by controlled hydrolyzation of tetraethyl orthosilicate and emulsion polymerization. [5][6][7][8] Using these colloidal templates, the Caruso group has prepared many kinds of porous hollow spheres and core-shell nanospheres through the "layer-by-layer" method, such as coating the spheres with noble-metal nanoparticles, metal oxide nanoparticles, polyelectrolytes, or biomolecules with specific electronic, optical, catalytic, and biological applications. 2,10 In recent years, much progress has been made on the preparation of monodisperse inorganic nanospheres. [11][12][13] For example, the Xia group has developed the glycol refluxing method to synthesize monodisperse metal micro or nanospheres, such as Bi, Pb, Se, metal alloys, and their functional core-shell structures. 11 Our group has developed the hydrothermal or solvothermal method to synthesize monodisperse micro-and nanospheres, such as chalcogenide, carbon, single-crystalline magnetic ferrite, and so forth. [12][13][14] By the template of carbon colloids, many hollow spheres, such as Ga 2 O 3 , GaN, WO 3 , and so forth have been prepared with special optical or sensor properties. 14 From above, it is concluded that because the intrinsic properties of monodisperse nanospheres can be finely tuned by changing parameters such as diameter, chemical composition, bulk structure, and crystallinity, searching for novel methods and preparing more kinds of monodisperse nanospheres are still required for some special applications. 6 Cuprous oxide (Cu 2 O), a p-type semiconductor with unique optical and magnetic properties, has potential applications in solar energy conversion, electronics, magnetic storage, catalysis, and gas sensors. CuO is also a potential material with many applications in catalysis, gas sensing, and lithium-copper oxide electrochemical cells. [15][16][17][18] CuO was the first kind of humidity sensing material found by Braver et al. in 1931. It was reported that Cu 2 O films had gas sensing activity at ∼200 °C. 16 Considering the potential applications of copper-based materials, many kinds of morphologies have been reported, such as wires, monodisperse nanocubes, octahedral nanocages, hollow nanospheres, and so forth. 15,17,18 Typically, the Zeng group used a solvothermal method in N,N-dimethylformamide (DMF) at 150-180 °C for 20-40 h to get hollow Cu 2 O nanospheres. They found the formation process of Cu 2 O hollow spheres included formation of CuO nanocrystals, aggregation of primary CuO nanocrystals, and the reductive transformation to C...

Atomic interface regulation is thought to be an efficient method to adjust the performance of single atom catalysts. Herein, a practical strategy was reported to rationally design single copper atoms coordinated with both sulfur and nitrogen atoms in metal-organic framework derived hierarchically porous carbon (S-Cu-ISA/SNC). The atomic interface configuration of the copper site in S-Cu-ISA/SNC is detected to be an unsymmetrically arranged Cu-S 1 N 3 moiety. The catalyst exhibits excellent oxygen reduction reaction activity with a half-wave potential of 0.918 V vs. RHE. Additionally, through in situ X-ray absorption fine structure tests, we discover that the low-valent Cuprous-S 1 N 3 moiety acts as an active center during the oxygen reduction process. Our discovery provides a universal scheme for the controllable synthesis and performance regulation of single metal atom catalysts toward energy applications.

The electrocatalytic reduction reaction of CO2 (CO2RR) is a promising strategy to promote the global carbon balance and combat global climate change. Herein, exclusive Bi-N4 sites on porous carbon networks can be achieved through thermal decomposition of a bismuth-based metal–organic framework (Bi-MOF) and dicyan­diamide (DCD) for CO2RR. Interestingly, in situ environmental transmission electron microscopy (ETEM) analysis not only directly shows the reduction from Bi-MOF into Bi nanoparticles (NPs) but also exhibits subsequent atomization of Bi NPs assisted by the NH3 released from the decomposition of DCD. Our catalyst exhibits high intrinsic CO2 reduction activity for CO conversion, with a high Faradaic efficiency (FECO up to 97%) and high turnover frequency of 5535 h–1 at a low overpotential of 0.39 V versus reversible hydrogen electrode. Further experiments and density functional theory results demonstrate that the single-atom Bi-N4 site is the dominating active center simultaneously for CO2 activation and the rapid formation of key intermediate COOH* with a low free energy barrier.

Patients with mutations showed unfavorable response to programmed cell death-1 (PD-1) blockade immunotherapy in non-small cell lung cancer (NSCLC). Yet the underlying association between mutation and immune resistance remains largely unclear. We performed an integrated analysis of PD-ligand 1(PD-L1)/CD8 expression and mutation profile based on the repository database and resected early-stage NSCLC in Guangdong Lung Cancer Institute (GLCI). Meanwhile, 2 pool-analyses were set to clarify the correlation between mutation and PD-L1 expression, and the association of status with response to anti-PD-1/L1 therapy. Pool-analysis of 15 public studies suggested that patients with mutations had decreased PD-L1 expression (odds ratio: 1.79, 95% CI: 1.10-2.93; P = 0.02). Analysis of The Cancer Genome Atlas (TCGA) and the GCLI cohort confirmed the inverse correlation between mutation and PD-L1 expression. Furthermore, patients with mutation showed a lack of T-cell infiltration and shrinking proportion of PD-L1/CD8 TIL (P = 0.034). Importantly, patients with mutations, especially the sensitive subtype, showed a significantly decreased mutation burden, based on analysis of the discovery and validation sets. Finally, a pool-analysis of 4 randomized control trials confirmed that patients with mutation did not benefit from PD-1/L1 inhibitors (Hazard ratio [HR] = 1.09, P = 0.51) while patients with wild-type did (HR = 0.73, P< 0.00001). This study provided evidence of a correlation between mutations and an uninflamed tumor microenvironment with immunological tolerance and weak immunogenicity, which caused an inferior response to PD-1 blockade in NSCLCs.