To address the shortcomings of conventional maximum power point tracking (MPPT) methods under rapidly changing environments, this paper proposes an improved linear active disturbance rejection control (ILADRC) strategy optimized by the twin-delayed deep deterministic policy gradient (TD3) algorithm. First, an ILADRC controller is designed within the variable-step incremental conductance (VS-INC) framework to enhance disturbance rejection capability. Then, the TD3 algorithm is employed to online tune three key ILADRC parameters—observer bandwidth ωo, controller bandwidth ωc, and control gain—eliminating the need for empirical manual tuning. Finally, simulations and hardware-in-the-loop (HIL) experiments validate the effectiveness of the proposed method. Results show that, compared with PI control, fixed-parameter LADRC, ILADRC, and DDPG-ILADRC, the TD3-ILADRC achieves faster and more accurate MPPT. It exhibits superior dynamic response and anti-disturbance performance under abrupt irradiance and temperature variations, reduces voltage and power fluctuations, improves generation efficiency and stability, and has strong engineering application value.
Friction and wear are unavoidable during the relative motion of mechanical components, while conventional liquid lubrication and physically blended systems are often limited by lubricant loss, interfacial instability and rapid performance degradation. Inspired by self-regulated lubricating interfaces, we report the construction of a silicone oil (HPSM) grafted acrylic self-lubricating coating (SLC), in which lubricating silicone oil units are covalently anchored to the polymer backbone. This molecular design enables stable lubricant immobilization and shear-induced migration, generating a sustained lubricating layer without compromising coating integrity. By tuning the pigment-to-binder ratio (PBR), an optimal balance between self-lubricating interface and mechanical robustness is achieved. The coating containing 20% HPSM with a pigment-to-binder ratio of 1.2 exhibits a low friction coefficient of 0.08 at 1 N and 1 Hz. It achieved an average drag reduction efficiency of 37% in a glycerol/water mixture with a mass ratio of 3:1 over the investigated shear-rate range. Stable low-friction and high drag-reduction performance are maintained under high shear and prolonged service conditions, highlighting a general molecular engineering strategy for durable friction regulation and fluid drag reduction.
Microbial electrosynthesis (MES) offers a promising carbon sequestration strategy for climate change mitigation, which also provides a sustainable pathway for biomass accumulation and bioenergy resource recovery. However, one key factor that governs electrosynthesis efficiency is electrode material. In this work, four electrodes including graphene electrodes (Gr), high-temperature calcined graphene electrodes (HG), graphene composite nanometal oxide with Fe2O3 (HFG) and TiO2 (HTG) were prepared to investigate the electroreduction effect on CO2 reduction activity, aiming to optimize the conversion of carbon resources into high-value biomass and renewable bioenergy products. The cathodic surface properties affect biofilm biomass and carbon-fixing bacteria abundance obviously. The biomass and electron transfer system activity (ETSA) were negatively correlated with charge transfer resistance. In comparison with the unmodified carbon felt as the cathode in the MES reactor, the acetic acid production in the subsequent four groups (388.62, 402.23, 441.77, and 489.81 mg/L) was significantly higher than that in the CF group (330.19 mg/L). As a typical bioenergy intermediate product, acetic acid is closely related to microbial biomass metabolism. Total carbon-fixing bacteria abundance was strongly positively correlated with acetic acid production (r = 0.914, p < 0.01). The Fe2O3 and TiO2 modified graphene cathodes enhanced both biofilm growth and carbon sequestration bacterial abundance respectively, optimized hydrogen evolution reaction kinetics and promoted the acetic acid production significantly.
3D printing has gained great attention in electrochemical CO2 reduction (CO2RR), however, its use in constructing self-supported catalytic electrodes with well-dispersed coordination active sites is still underdeveloped. In this study, a catalytic electrode with CoNX coordination structures (3D-CE-CoNX) was successfully fabricated using 3D printing for syngas production via CO2RR. The CO2RR reaction was conducted in a H-type electrolyzer, which was equipped with a conventional three-electrode system. Electrochemical tests show that 3D-CE-CoNX, carbonized at 700 degrees C, exhibits good CO2 reduction activity within the potential range of -0.6 V to -1.0 V, producing syngas with a H2:CO ratio ranging from 0.53 to 1.79, which is tunable mainly by the applied potential. At -0.7 V, the current density for CO (JCO) is -0.19 mA cm- 2, while for H2 (JH2)is -0.14 mA cm- 2. After 24 h of continuous electrolysis, 3D-CE-CoNX maintains 91.5% of its initial CO faradaic efficiency (FECO). Furthermore, Xray absorption fine structure (XAFS) characterization confirms the successful incorporation of CoNX sites, validating the electrode's effectiveness. This study highlights the unique advantages of 3D printing in catalytic electrode construction and provides a feasible pathway for obtaining high-performance catalytic electrodes for future energy conversion applications.
The development of catalytic electrode by 3D printing technology has become a hot spot. In this study, a catalytic electrode for CO2 reduction reaction (CO2RR) (named DIW-FePc-CE) was fabricated using direct ink writing (DIW) 3D printing technology, with iron phthalocyanine (FePc) was loaded at varying concentrations via an impregnation method. The results showed that, CO was the main product and H2 was the only by-product (small amounts) on as-prepared DIW-FePc-CE. Notably, the optimal DIW-FePc-CE (carbonized at 950 degrees C and soaking with 8 g L- 1 FePc) showed high selectivity for electroreduction conversion of CO2 into CO with a high Faraday efficiency (FECO) of 63.3 %. And the FECO was basically stabilized for 8 h of continuous electrolysis. This study fabricated catalytic electrodes for CO2RR, offering a valuable reference for the development of other advanced catalytic electrodes using DIW technology.
