Spontaneous Compositional-Interfacial Co-Modification Engineering via Ion Exchange Reaction Between Perovskite and Electron-Transporting Layer for Exceptionally Long-Term Stability of Photovoltaics.

The long-term stability of perovskite solar cells (PSCs) is still challenging for commercialization and mainly linked to the life span of perovskite films. Herein, a spontaneous compositional-interfacial co-modification strategy is developed based on the ion exchange reaction by introducing ammonium hexafluorophosphate (NH4PF6) into antisolvent to form gradient structures through a simple one-step solvent engineering. With the assistance of the ion exchange reaction, NH4PF6 forms a multifunctional structure to protect perovskite films from both internal and external factors for the exceptionally long-term stability of photovoltaics. The reason for this is linked to the high hydrophobicity of NH4PF6 for preventing H2O invasion, suppressing ion migration by forming hydrogen bonding, and reducing perovskite defects. The resulting unencapsulated devices show exceptionally long-term stability under standardized the International Summit on Organic Photovoltaic Stability (ISOS) protocols, with over 94%, 81%, and 83% retained power conversion efficiencies after aging tests under N2 (ISOS-D-1I), ambient air (ISOS-D-1), and 85 °C (ISOS-D-2I) for 14016, 2500, and 1248 h, respectively. These performances compare well with the state-of-the-art stability of inverted PSCs. Further investigations are conducted to study the evolution of macroscopic morphology and microscopic crystal structure in aged perovskite films, aiming to provide evidence supporting the aforementioned improvements in stability.

Upregulation of CD226 on subsets of T cells and NK cells is associated with upregulated adhesion molecules and cytotoxic factors in patients with tuberculosis.

Human T cells and natural killer (NK) cells are major effector cells of innate immunity exerting potential immune surveillance against tuberculosis infection. CD226 is an activating receptor playing vital roles in the functions of T cells and NK cells during HIV infection and tumorigenesis. However, CD226 is a less-studied activating receptor during Mycobacterium tuberculosis (Mtb) infection. In this study, we used peripheral blood from tuberculosis patients and healthy donors to evaluate CD226 immunoregulation functions from two independent cohorts using Flow cytometry. Here, we found that a subset of T cells and NK cells that constitutively express CD226 exhibit a distinct phenotype in TB patients. In fact, the proportions of CD226+ and CD226- cell subsets differ between healthy people and tuberculosis patients, and the expression of immune checkpoint molecules (TIGIT, NKG2A) and adhesion molecules (CD2, CD11a) in CD226+ and CD226- subsets of T cells and NK cells exhibits special regulatory roles. Furthermore, CD226+ subsets produced more IFN-γ and CD107a than CD226- subsets in tuberculosis patients. Our results imply that CD226 may be a potential predictor of disease progression and clinical efficacy in tuberculosis by mediating the cytotoxic capacity of T cells and NK cells.

Constructing Soft Perovskite-Substrate Interfaces for Dynamic Modulation of Perovskite Film in Inverted Solar Cells with Over 6200 Hours Photostability.

High-performance perovskite solar cells (PSCs) depend heavily on the quality of perovskite films, which is closely related to the lattice distortion, perovskite crystallization, and interfacial defects when being spin-coated and annealed on the substrate surface. Here, a dynamic strategy to modulate the perovskite film formation by using a soft perovskite-substrate interface constructed by employing amphiphilic soft molecules (ASMs) with long alkyl chains and Lewis base groups is proposed. The hydrophobic alkyl chains of ASMs interacted with poly(triarylamine) (PTAA) greatly improve the wettability of PTAA to facilitate the nucleation and growth of perovskite crystals, while the Lewis base groups bound to perovskite lattices significantly passivate the defects in situ. More importantly, this soft perovskite-substrate interface with ASMs between PTAA and perovskite film can dynamically match the lattice distortion with reduced interfacial residual strain upon perovskite crystallization and thermal annealing owing to the soft self-adaptive long-chains, leading to high-quality perovskite films. Thus, the inverted PSCs show a power conversion efficiency approaching 20% with good reproducibility and negligible hysteresis. More impressively, the unencapsulated device exhibits state-of-the-art photostability, retaining 84% of its initial efficiency under continuous simulated 1-sun illumination for more than 6200 h at elevated temperature (≈65 °C).

Resonance-Mediated Dynamic Modulation of Perovskite Crystallization for Efficient and Stable Solar Cells.

Manipulating perovskite crystallization to prepare high-quality perovskite films is the key to achieving highly efficient and stable perovskite solar cells (PSCs). Here, a dynamic strategy is proposed to modulate perovskite crystallization using a resonance hole-transporting material (HTM) capable of fast self-adaptive tautomerization between multiple electronic states with neutral and charged resonance forms for mediating perovskite crystal growth and defect passivation in situ. This approach, based on resonance variation with self-adaptive molecular interactions between the HTM and the perovskite, produces high-quality perovskite films with smooth surface, oriented crystallization, and low charge recombination, leading to high-performance inverted PSCs with power conversion efficiencies approaching 22% for small-area devices (0.09 cm2 ) and up to 19.5% for large-area devices (1.02 cm2 ). Also, remarkably high stability of the PSCs is observed, retaining over 90%, 88%, or 83% of the initial efficiencies in air with relative humidity of 40-50%, under continuous one-sun illumination, or at 75 °C annealing for 1000 h without encapsulation.

Removal of phosphorus and ammonium from municipal wastewater treatment plant effluent by manganese ore in a simulated constructed wetland.

Natural manganese ore (NM) is selected as a distinguished constructed wetland (CW) substrate for nutrient pollutants removal, however, the study on municipal wastewater treatment plant (WWTP) effluent treatment remains scarce. The current study was to investigate the sorption characteristics of NM and the removal efficiency of ammonium and phosphorus from one WWTP effluent in a simulated vertical flow NM constructed wetland (NM-VFCW). Results indicated that NM could effectively sorb ammonium and phosphorus within 24 h, and the desorption ratio was less than 7%. The sorption of ammonium and phosphorus enhanced when increasing the particle size of NM, but was not sensitive with temperature. The removal efficiencies for ammonium and phosphorus were 65% and 76% in NM-VFCW, which were 61% and 31% in gravel VFCW. The much higher removal efficiency for phosphorus was mainly attributed to the precipitation of phosphorus which was identified by the SEM and EDS spectrum. Therefore, the manganese ore sand is highlighted as a powerful substrate for simultaneous advanced removal of phosphorus and ammonium in constructed wetland systems.

Adsorption of Strontium onto Adaxial and Abaxial Cuticle of Photinia serrulata Leaf.

Leaf cuticle sorption is one important process for the uptake of environment pollutants in plants, and mixed powder including adaxial and abaxial cuticle is generally used to demonstrate the sorption behavior. However, the difference of adaxial and abaxial cuticle on plant cuticle sorption is not well understood. Abaxial cuticle (PAC) and adaxial cuticle (PBC) were isolated from hypostomatic Photinia serrulata to investigate their adsorption of a model radionuclide (strontium). The elemental composition and FTIR spectra for two cuticles were quite similar and both show high affinity (H/C, 1.59 and 1.65) and polarity ((O + N)/C, 0.470 and 0.499). Both adsorption isotherms fit well with Langmuir model (R2, 0.97 and 0.97), and the maximum adsorption capacity of PAC was 12.1 mg/g, little higher than that of PBC (10.3 mg/g). Adsorption of strontium increased with the increase of pH, and the maximum was attained when pH ≥4. Electrostatic attraction was demonstrated to be the main mechanism of -strontium adsorption onto PAC and PBC, and the similar adsorption of adaxial and abaxial cuticle was consistent with their similar isoelectric point.