Frontiers in Energy最新文献

The challenges posed by climate change and greenhouse gas net-zero transition are discussed. Several key technology areas which require innovation are briefly reviewed in this article, including renewables, energy storage, distributed energy resources, CO₂ utilization, agriculture, and the synergy between Al and energy transition. The shift in mindset from “re-cycling” to “re-using” and a redefinition of “wealth” for a more sustainable future are also proposed.

Bioluminescent plankton are marine organisms capable of emitting visible light through chemical reactions in their bodies. This unique biochemical trait is attributed to a luciferin-luciferase reaction, which produces a striking blue light. This fascinating phenomenon, often referred to as the “blue tears” effect, has become a major attraction for tourist attractions in many countries. Since their discovery, most investigations related to these marine organisms have primarily focused on the fields of biology, ecology, oceanography, and microbiology. However, there has been limited to almost no study of their potential applications in the area of energy or lighting. This paper provides viewpoints on the opportunities for using these marine organisms and their light-emitting characteristics as an energy-efficient and environmentally friendly lighting solution, rather than just as a tourist attraction. Additionally, it addresses the challenges associated with sustaining the growth of bioluminescent plankton collected from the marine environment, the importance of establishing suitable protocols for in-house cultivation, challenges in stimulating the light-production at desired time, constraint imposed by the circadian rhythm, the toxicity of certain bioluminescent plankton, and the capacity of their luminous intensity.

Mesoporous biochar (MC) derived from biomass is synthesized using a dual-salt template method involving ZnCl₂ and KCl, followed by impregnation with polyethyleneimine (PEI) of varying average molecular weights under vacuum conditions to construct a core-membrane structure for enhancing carbon capture performance. The resulting MC exhibits a highly intricate network of micropores and abundant mesopores, along with defects in graphitic structures, effectively facilitating robust PEI loading. Among the PEI-modified samples, PEI-600@MC demonstrates the highest CO₂ sorption capacity, achieving approximately 3.35 mmol/g at 0.1 MPa and 70 °C, with an amine efficiency of 0.32 mmol CO₂/mmol N. The introduction of amine functional groups in PEI significantly enhances the sorption capacity compared to bare MC. Additionally, PEI with lower average molecular weights exhibits a superior sorption performance at low pressures but shows a reduced thermal stability compared to higher molecular weight counterparts. The area of sorption hysteresis loops gradually decreases with increasing temperature and average molecular weight of PEI. The equilibrium sorption isotherms are accurately modeled by the Langmuir equation, revealing a maximum sorption capacity of approximately 3.53 mmol/g at 70 °C and saturation pressure. This work highlights the potential of dual-salts templated biomass-derived MC, modified with PEI, as an effective, widely available, and cost-efficient material for CO₂ capture.

NiFe (oxy)hydroxide (NiFeOOH) is recognized as a highly active non-precious metal catalyst in alkaline water electrolysis due to its exceptional catalytic properties. In this work, high valence molybdenum (Mo) is introduced to improve the electronic structure and enhance the electrical conductivity of NiFeOOH for oxygen evolution reaction (OER). The introduction of Mo results in a Mo-doped NiFeOOH catalyst with a significantly reduced overpotential of 205 mV at 10 mA/cm² and a Tafel slope of 31.7 mV/dec, enabling stable operation for up to 170 h. Both empirical experiment and theory simulations are employed to gain insight into the 3d-electron interactions between molybdenum and nickel (Ni), iron (Fe) in Mo-doped NiFeOOH. The results indicate that Mo-doping enhances the valence states of Ni and Fe, leading to a shift in the d-band center of the bimetallic active sites. This modification affects the transformation of Mo-doped NiFeOOH into the γ-NiFeOOH active phase. This potent combination lends credence to its potential suitability and utility in OER applications.

Ammonia is an exceptional fuel for solid oxide fuel cells (SOFCs), because of the high content of hydrogen and the advantages of carbon neutrality. However, the challenge lies in its unsatisfactory performance at intermediate temperatures (500–600 °C), impeding its advancement. An electrolyte-supported proton-ceramic fuel cell (PCFC) was fabricated employing BaZr_0.1Ce_0.7Y_0.2O_3−δ (BZCY) as the electrolyte and Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ (BSCF) as the cathode. In this study, the performance of PCFC using NH₃ as fuel within an operating temperature range of 500–700 °C was improved by adding an M(Ni,Ru)/CeO₂ catalyst layer to reconstruct the anode surface. The electrochemical performance of direct ammonia PCFC (DA-PCFC) were improved to different extents. Compared to H₂ as fuel, the degradation ratio of peak power densities (PPDs) of Ni/CeO₂-loaded PCFC fueled with NH₃ decreased at 700–500 °C, with a decrease to 13.3% at 700 °C and 30.7% at 500 °C. The findings indicate that Ru-based catalysts have a greater promise for direct ammonia SOFCs (DA-SOFCs) at operating temperatures below 600 °C. However, the enhancement effect becomes less significant above 600 °C when compared to Ni-based catalysts.

Fe-N-C catalysts are potential substitutes to displace electrocatalysts containing noble chemical elements in the oxygen reduction reaction (ORR). However, their application is hampered by unsatisfactory activity and stability issues. The structures and morphologies of Fe-N-C catalysts have been found to be crucial for the number of active sites and local bonding structures. In this work, dicyandiamide (DCDA) and polyaniline (PANI) are shown to act as dual nitrogen sources to tune the morphology and structure of the catalyst and facilitate the ORR process. The dual nitrogen sources not only increase the amount of nitrogen doping atoms in the electrocatalytic Fe-C-N material, but also maintain a high nitrogen-pyrrole/nitrogen-graphitic: (N-P)/(N-G) value, improving the distribution density of catalytic active sites in the material. With a high surface area and amount of N-doping, the Fe-N-C catalyst developed can achieve an improved half-wave potential of 0.886 V (vs. RHE) in alkaline medium, and a better stability and methanol resistance than commercial Pt/C catalyst.