Dynamical Janus-Like Behavior Excited by Passive Cold-Heat Modulation in the Earth-Sun/Universe System: Opportunities and Challenges.

The utilization of solar-thermal energy and universal cold energy has led to many innovative designs that achieve effective temperature regulation in different application scenarios. Numerous studies on passive solar heating and radiation cooling often operate independently (or actively control the conversion) and lack a cohesive framework for deep connections. This work provides a concise overview of the recent breakthroughs in solar heating and radiation cooling by employing a mechanism material in the application model. Furthermore, the utilization of dynamic Janus-like behavior serves as a novel nexus to elucidate the relationship between solar heating and radiation cooling, allowing for the analysis of dynamic conversion strategies across various applications. Additionally, special discussions are provided to address specific requirements in diverse applications, such as optimizing light transmission for clothing or window glass. Finally, the challenges and opportunities associated with the development of solar heating and radiation cooling applications are underscored, which hold immense potential for substantial carbon emission reduction and environmental preservation. This work aims to ignite interest and lay a solid foundation for researchers to conduct in-depth studies on effective and self-adaptive regulation of cooling and heating.

Cerium Doping-Induced Enrichment of Ni3S4 Phase for Boosting Oxygen Evolution Reaction.

The development of low-cost transition metal compounds with high-performance for efficient oxygen evolution reaction (OER) is of great significance in promoting the development of electrocatalysis. In this study, a Ce-doped Ni3S4 catalyst (Ce0.2-Ni3S4) was synthesized through a one-step solvothermal method, where the doped rare earth element Ce induced the transformation of NiS to Ni3S4. The Ce0.2-Ni3S4 catalyst exhibited excellent OER performance in 1 M KOH. At a current density of 10 mA cm-2, it showed a low overpotential of 230 mV and a low Tafel slope of 52.39 mV dec-1. Long-term OER tests at the same potential lasted for 24 h without significant loss of current density. This work introduces a novel method of Ce element doping for modifying transition metal sulfides, providing new insights into the effective utilization of rare earth elements in the field of electrochemistry. It creates more chances for the progress of highly efficient catalysts for efficient OER, contributing to the advancement of electrocatalysis.

Magnetic hydrochar grafted-chitosan for enhanced efficient adsorption of malachite green dye from aqueous solutions: Modeling, adsorption behavior, and mechanism analysis.

Water pollution by organic dyes is one of the most serious environmental problems worldwide. Malachite green (MG) is considered as one the serious organic dyes which is discharged in wastewater by leather and textile manufacturing plants. MG dye can cause severe hazards to the environment and human health. Therefore, the removal of MG dye from wastewater is very important and essential. This study aims to synthesize a new magnetic hydrochar grafted to chitosan (MWSHC@CS) for the removal of MG dye from the aqueous solutions. Transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, and Zeta potential analysis were used to characterize the synthesized MWSHC@CS. Batch experiments were conducted to optimize MG dye adsorption conditions, including adsorbent mass, pH, temperature, initial concentration, and contact time. The results revealed that MWSHC@CS had an excellent removal efficiency (96.47 %) for MG dye at the optimum condition (at m: 20 mg, pH: 7.5, t: 420 min, and T: 298 K). Adsorption isotherms outcomes revealed the MG adsorption data were best fit by the Langmuir model with a maximum adsorption capacity (420.02 mg/g). Adsorption kinetics outcomes exhibited that the adsorption process of MG dye fitted well to the Elovich model. The thermodynamic results revealed that the adsorption process was physical, exothermic, and spontaneous. The adsorption mechanisms of MG onto MWSHC@CS were hydrogen bonding, electrostatic interaction, and π-π interactions. Furthermore, MWSHC@CS showed excellent reusability for the removal of MG over five cycles of adsorption-desorption (83.76 %). In conclusion, the study provides a new, low-cost, and effective magnetic nanocomposite based on chitosan as a promising adsorbent for the high-performance removal of MG dye from aqueous solutions.

Moisture Power Generation: From Material Selection to Device Structure Optimization.

Moisture power generation (MPG) technology, producing clean and sustainable energy from a humid environment, has drawn significant attention and research efforts in recent years as a means of easing the energy crisis. Despite the rapid progress, MPG technology still faces numerous challenges with the most significant one being the low power-generating performance of individual MPG devices. In this review, we introduce the background and underlying principles of MPG technology while thoroughly explaining how the selection of suitable materials (carbons, polymers, inorganic salts, etc.) and the optimization of the device structure (pore structure, moisture gradient structure, functional group gradient structure, and electrode structure) can address the existing and anticipated challenges. Furthermore, this review highlights the major scientific and engineering hurdles on the way to advancing MPG technology and offers potential insights for the development of high-performance MPG systems.

Cellulose nanofibers-based composite film with broadening MXene layer spacing and rapid moisture separation for humidity sensing and humidity actuators.

Based on the basic idea of expanding the interlayer spacing of MXene, utilizing the effect of gallic acid-modified cellulose nanofibers for rapid moisture separation, the flexible sensing and driving composite film with a perfect balance among humidity signal response and mechanical properties was prepared. Inspired by the stacking of autumn fallen leaves, the cellulose nanofibers-based composite films were formed by self-assembly under vacuum filtration of blending gallic acid-modified cellulose nanofibers with MXene. The enhanced mechanical properties (tensile strength 131.1 MPa, puncture load 0.88 N, tearing strength 165.55 N/mm, and elongation at break 16.14 %), humidity sensing (the stable induced voltage 63.7 mV and response/recovery time 3.2/5.1 s), and humidity driving (154.7° bending angle) properties were observed. The synergistic effect of hydrogen bonds, the "pinning effect" arising from the side chains, and the hierarchical layered microstructure contributed to the enhanced performance. This work exemplifies the application of green natural product for preparing intelligent sensing, wearable devices, and biomimetic robots.

Polyvinyl alcohol/sodium alginate-based conductive hydrogels with in situ formed bimetallic zeolitic imidazolate frameworks towards soft electronics.

Bimetallic zeolitic imidazolate frameworks (BZIFs) have received enormous attention due to their unique physi-chemical properties, but are rarely reported for electrically conductive hydrogel (ECH) applications arising from low intrinsic conductivity and poor dispersion. Herein, we propose an innovative strategy to prepare highly conductive and mechanically robust ECHs by in situ growing Ni/Co-BZIFs within the polyvinyl alcohol/sodium alginate dual network (PZPS). 2-methylimidazole (MeIM) ligands copolymerize with pyrrole monomers, enhancing the electrical conductivity; meanwhile, MeIM ligands act as anchor points for in-situ formation of BZIFs, effectively avoiding phase-to-phase interfacial resistance and ensuring a uniform distribution in the hydrogel network. Due to the synergism of Ni/Co-BZIFs, the PZPS hydrogel exhibits a high areal capacitance of 630.3 mF·cm-2 at a current density of 0.5 mA·cm-2, promising for flexible energy storage devices. In addition, PZPS shows excellent mechanical strength and toughness (with an ultimate tensile strength of 405.0 kPa and a toughness of 784.2 kJ·m-3 at an elongation at break of 474.0 %), a high gauge factor of up to 4.18 over an extremely wide stress range of 0-42 kPa when used as flexible wearable strain/pressure sensors. This study provides new insights to incorporating highly conductive and uniformly dispersed ZIFs into hydrogels for flexible wearable electronics.

Insight into the corrosion mitigation performance of three novel benzimidazole derivatives of amino acids for carbon steel (X56) in 1 M HCl solution.

Three new organic molecules having a benzimidazole base were synthesized and used for the protection of carbon steel (X56) against corrosion in 1.00 M HCl solution. The protection against corrosion was assessed by electrochemical frequency modulation (EFM), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). In addition, the electronic and molecular structure of the synthesized molecules were computationally investigated and correlated to corrosion inhibition. Global reactivity descriptors, molecular orbitals (FMO and NBO) and local reactivity descriptors (molecular electrostatic potential map and Fukui functions) were discussed. The results showed a maximum protective efficiency range between 95% and 98% indicating high corrosion inhibition. Moreover, all molecules were able to combat the cathodic as well as anodic reaction simultaneously, revealing a mixed-type resistance. SEM and EDX verified effective adhering film formation to the metal surface. In accordance, the theoretical calculations showed effective electron reallocation from the organic film to the X56 c-steel surface. Furthermore, the adsorption annealing calculations revealed that structural layers of these molecules hold parallel and close to the metal surface with adsorption energy from 249.383 to 380.794 kcal mol-1, showing strong inhibitor-metal contact.

Preparation and Characterization of Physically Activated Carbon and Its Energetic Application for All-Solid-State Supercapacitors: A Case Study.

Biomass-derived activated carbons have gained significant attention as electrode materials for supercapacitors (SCs) due to their renewability, low-cost, and ready availability. In this work, we have derived physically activated carbon from date seed biomass as symmetric electrodes and PVA/KOH has been used as a gel polymer electrolyte for all-solid-state SCs. Initially, the date seed biomass was carbonized at 600 °C (C-600) and then it was used to obtain physically activated carbon through CO2 activation at 850 °C (C-850). The SEM and TEM images of C-850 displayed its porous, flaky, and multilayer type morphologies. The fabricated electrodes from C-850 with PVA/KOH electrolytes showed the best electrochemical performances in SCs (Lu et al. Energy Environ. Sci., 2014, 7, 2160) application. Cyclic voltammetry was performed from 5 to 100 mV s-1, illustrating an electric double layer behavior. The C-850 electrode delivered a specific capacitance of 138.12 F g-1 at 5 mV s-1, whereas it retained 16 F g-1 capacitance at 100 mV s-1. Our assembled all-solid-state SCs exhibit an energy density of 9.6 Wh kg-1 with a power density of 87.86 W kg-1. The internal and charge transfer resistances of the assembled SCs were 0.54 and 17.86 Ω, respectively. These innovative findings provide a universal and KOH-free activation process for the synthesis of physically activated carbon for all solid-state SCs applications.

Effective corrosion inhibition of mild steel in hydrochloric acid by newly synthesized Schiff base nano Co(ii) and Cr(iii) complexes: spectral, thermal, electrochemical and DFT (FMO, NBO) studies.

Two new cobalt(ii) and chromium(iii) complexes were synthesized and characterized by FT-IR, 1HNMR, UV, elemental analysis, TGA, conductivity, XRD, SEM, and magnetic susceptibility measurements. Structural analysis revealed a bi-dentate chelation and octahedral geometry for the synthesized complexes. The optical band gap of the Co(ii)-L and Cr(iii)-L complexes was found to be 3.00 and 3.25 eV, respectively revealing semiconducting properties. The X-ray diffraction patterns showed nano-crystalline particles for the obtained complexes. In addition, the synthesized metal complexes were examined as corrosion inhibitors for mild steel in HCl solution. The electrochemical investigations showed a maximum inhibition efficiency of 96.60% for Co(ii)-L and 95.45% for Cr(iii)-L where both complexes acted as mixed-type inhibitors. Frontier Molecular orbital (FMO) and Natural bond orbital (NBO) computations showed good tendency of the ligand to donate electrons to the metal through nitrogen atoms while the resultant complexes tended to donate electrons to mild steel more effectively through oxygen atoms and phenyl groups. A comparison between experimental and theoretical findings was considered through the discussion.

Removal of azo dye from aqueous solution by a low-cost activated carbon prepared from coal: adsorption kinetics, isotherms study, and DFT simulation.

The high-risk organic pollutants produced by industries are of growing concern. The highly porous coal-based activated carbon (AC) having a specific surface area of 3452.8 m2/g is used for the adsorption of azo dye from synthetic solution. The sorbent is characterized through BET, SEM, TEM, XRD, FT-IR, TGA, and zeta potential. The sorbent exhibits - 18.7 mV surface charge, which is high enough for making suspension. The maximum dye uptake of 333 mg/g is observed in sorbent under acidic medium. The thermodynamics parameters like ∆G, ∆H, and ΔS were found to be - 12.40 kJ mol-1, 39.66 kJ mol-1, and 174.55 J mol-1 K-1 at 293 K, respectively, revealing that the adsorption mechanism is spontaneous, endothermic, and feasible. The experimental data follows the Langmuir and D-R models. The adsorption follows pseudo 2nd-order kinetics. DFT investigation shows that the dye sorption onto AC in configuration No. 4 (CFG-4) is more effective, as this configuration has high ∆H (enthalpy change) and adsorption energy (Eads). This is confirmed by Mullikan atomic charge transfer phenomenon.