Photoelectrochemical CO2 reduction (PECR) offers a direct route to utilize CO2 while simultaneously storing solar energy in fuels and chemicals. However, Photocathode performance is often limited by weak light harvesting, rapid recombination of photo-generated electron-hole pairs, sluggish interfacial charge transfer, and photocorrosion. In this work, we present a TiO2-Pt-Cu2O heterojunction photocathode, where the sputtered Pt interlayer mediates the formation of an indirect Z-scheme charge transfer. This not only mitigates the recombination of electron-hole pairs but also preserves highly reducing electrons in Cu2O. The TiO2-Pt-Cu2O photocathode shows a photocurrent density of jTiO2-Pt-Cu2O = -6.121 mA/cm2, a methanol formation rate RCH3OH of similar to 117.6 & micro;molcm-2h-1, with its faradic efficiency similar to 63%, and synergy factor (SF) of 4.96 at an applied potential of -0.5 V vs. Ag/AgCl, surpassing TiO2 (jTiO2 = -0.133 mA/cm2, RCH3OH = 9.18 & micro;molcm-2h-1) and a binary TiO2-Cu2O type-II junction (jTiO2-Cu2O = -0.73 mA/cm2, RCH3OH = 21.65 & micro;molcm-2h-1). Furthermore, we investigated the role of Pt introduction to elucidate the detailed charge transfer mechanisms using characterisation techniques such as XPS and PL, complemented by DFT. Electrochemical and DFT analysis revealed the favorable interfacial energetics and lowered charge-transfer resistance in Cu2O(100)-Pt-TiO2(101) junction. These findings guide rational material design for sustainable CO2 reduction.
ABSTRACT The escalating demand for high‐energy‐density lithium‐ion batteries necessitates cathode materials capable of stable operation at elevated voltages, yet the widespread adoption of LiCoO 2 (LCO) at ≥ 4.6 V is severely hampered by structural degradation and parasitic interfacial reactions. Here, we report a rationally designed series of fluorinated acrylonitrile copolymers (A9F1) synthesized via miniemulsion polymerization, in which the proportions of cyano, ester, and fluorinated side‑chain groups are systematically tuned. The A9F1 binder, with a balanced composition, concurrently delivers adequate adhesion (peel strength of 4.17 N cm −1 ), superior hydrophobicity (water contact angle of 125°), and excellent electrolyte compatibility (swelling ratio of 26.32%). More importantly, the electron‑withdrawing fluorinated moieties raise the electrode‐level oxidative stability to 4.73 V, while the cyano and ester groups synergistically facilitate rapid Li + transport and foster the formation of a thin, LiF‑rich cathode electrolyte interphase (CEI). As a result, LCO||Li half‑cells with A9F1 retain 88.23% capacity after 250 cycles at 1 C under 4.6 V, and high‑loading electrodes (≈12 mg cm −2 ) achieve 82.99% retention over 200 cycles. In practical LCO||graphite full cells, A9F1 delivers an 88.53% capacity retention after 300 cycles, far surpassing the 60.14% of PVDF.
ABSTRACT The development of sustainable and efficient energy‐harvesting materials is essential for the growing demand for self‐powered electronic devices. In this study, red chilli pericarp (CP) powder was investigated as a renewable bio‐filler for developing poly(vinyl alcohol) (PVA)‐based triboelectric nanogenerators (TENGs). Four different chilli varieties, namely Kashmiri (KCP), Byadagi (BCP), Gunturu (GCP), and Salem Gundu (SCP), were incorporated into PVA using a simple solution‐casting technique. The influence of the chilli pericarp on the structural, morphological, surface, thermal, and triboelectric properties of the resulting bio‐composites was systematically investigated. XRD, SEM, and FTIR analyses confirmed the structural characteristics, irregular morphology, and interaction between the CP and PVA matrix. The incorporation of CP also improved the surface properties of PVA by increasing hydrophobicity and reducing surface energy. Among the composites, BCP/PVA exhibited improved thermal stability, while KCP had the smallest Z‐average particle size, 1206 nm. The prepared CP/PVA composites were used as tribopositive layers for TENG fabrication. Among the different devices, the 2.0 wt% KCP/PVA‐TENG exhibited the highest electrical output, generating a voltage of 310 V and a current of 32 µA, which is significantly higher than that of pristine PVA. The generated electrical energy was successfully demonstrated for illuminating 61 LEDs, charging capacitors, and distinguishing different fabric surfaces, highlighting its potential for tactile sensing. These results demonstrate that red CP can serve as an effective, low‐cost, and renewable bio‐filler for improving the triboelectric performance of PVA. The proposed bio‐composite TENG provides a simple and sustainable approach for mechanical energy harvesting and self‐powered sensing applications.
ABSTRACT The rapid development of the lithium‐ion battery industry produces large quantities of spent graphite anodes. Spent graphite contains abundant intrinsic defects, and residual Ni, Co, and Mn impurities still persist even after intensive purification, resulting in low utilization efficiency and poor economic benefits for traditional graphite recycling. Herein, this work proposes a defect‐engineered upcycling strategy to in situ utilization of residual impurities on waste graphite and fabricate trimetallic‐anchored reduced graphene oxide catalysts (rSGO‐NiCoMn) for tetracycline (TC) degradation by peroxymonosulfate activation. Defect sites of spent graphite can effectively anchor the metal ions. Benefiting from the synergistic redox effect between metal active sites and defective carbon skeletons, the catalyst can effectively degrade TC, with sulfate and hydroxyl radicals as the dominant active species. The catalyst displays broad pH adaptability, excellent water matrix anti‐interference ability, and favorable cycling stability. Life cycle assessment demonstrates that compared with traditional graphite regeneration technologies, this process greatly reduces the energy consumption, water consumption and greenhouse gas emission, with increased economic benefits. Without thorough impurity removal, this strategy enables synchronous resource utilization of carbon substrates and transition metals, providing sustainable candidate toward green recycling of waste graphite and efficient antibiotic wastewater treatment.
ABSTRACT The transition to a circular economy requires scalable routes for upcycling hazardous waste into high‐value functional materials. Here, we report a synthesis of magnetic zinc ferrite/maghemite‐based nanoadsorbents utilizing precursors recovered entirely from spent batteries and oxidized iron scrap. Energy Loss Magnetic Chiral Dichroism (EMCD) measurements under matched experimental conditions revealed about 18% stronger EMCD response for ZnF‐Ni than for unmodified ZnFe 2 O 4 . In addition, ZnF‐Ni enabled substantially faster overall treatment through the combined adsorption and magnetic separation procedure, reducing the processing time to approximately 10–15 min compared with approximately 24 h for ZnF. Magnetic separation facilitates a pH‐switchable process where dyes are removed via protonated surface hydroxyls and subsequently released in alkaline media. We successfully validated a continuous, flow‐through remediation prototype that instantaneously traps the dye‐nanoabsorbent in situ by an external magnetic field from a moving suspension stream, followed by dye release and material recovery. This study presents a techno‐economically practical pathway for e‐waste utilization, showing reaction‐based theoretical atom economy of ∼77% for spinel ferrite formation.
