Biodiesel is a renewable fuel and could offer a sustainable, carbon-neutral alternative to petroleum products. Yet production costs remain a hurdle to its widespread use. Now, researchers have developed an inexpensive way to make biodiesel from materials found along the banks of their Louisiana bayou: algae and oyster shells. The researchers will present their results at ACS Spring 2026.

ITU, the UN agency for digital technologies, will host the seventh AI for Good Global Summit from 7 to 10 July 2026 at Geneva’s Palexpo convention centre. Over four days, leaders from government, industry, academia, civil society and the technical community will work together at AI for Good to guide the future of AI.

Aqueous Zn-ion batteries (AZIBs) have been considered promising energy storage systems due to their low cost, high safety and environmental friendliness. Manganese dioxide (MnO₂) is a practically desirable cathode material for AZIBs; however, it is challenged by poor structural stability and unsatisfactory storage reversibility. Given the distinct advantages and limitations of single-phase MnO₂, Herein, constructing a dual-crystal-phases structure is proposed an effective strategy to comprehensively improve the storage capacity, rate capability, and cycling stability of AZIBs. NH⁺₄ cations are ingeniously introduced to the hydrothermal reaction system to precisely regulate crystalline phases of MnO₂. An optimal NH⁺₄ concentration endows the coexistence of α/δ-MnO₂ crystal phases with abundant heterogenous phase interfaces. The mismatch of the heterogenous crystal lattices results in abundant active structural defects at the dual-crystal-phases interfaces for efficient ionic storage and fast electronic/ionic transport. The heterogenous interfaces further enable structural stability of the MnO₂ cathode without structural deformation during cycling, thus enhancing the cycling performance of AZIBs. Electrochemical tests show that the α/δ-MnO₂ cathode provides a remarkable specific capacity of 297.6 mAh/g at 1 C, excellent rate performance (210.1 mAh/g at 3 C), and superior cycling stability (93.7% capacity retention after 600 cycles at 1 C). Moreover, flexible AZIBs based on the α/δ-MnO₂ cathode remain stable operation under bending conditions, demonstrating the practical potential of the α/δ-MnO₂ architecture. This study presents an innovative material design strategy for high-performance AZIB cathodes via dual-crystal-phase engineering, which can be extended to other electrode materials beyond AZIBs.

Engineering active sites in a controllable manner plays a critical role in developing catalysts with desired catalytic performance. A reliable and tunable molecular engineering strategy is presented to boost the oxygen reduction reaction (ORR) performance of single-atom catalysts (SACs) by manipulating the steric hindrance effect of metalloporphyrins. The results demonstrate that the metalloporphyrin molecules with four tert-butylphenyl groups as steric hindrance moieties can be used to prepare various SACs with targeted active sites on conductive carbon black (CB). It is found that the single iron catalyst on CB prepared using tert-butylphenyl iron-porphyrins as a precursor (denoted as t-Fe-800/CB) exhibits significantly enhanced ORR performance compared with the Fe-800/CB catalyst prepared from unsubstituted iron-porphyrin. Moreover, the t-Fe-800/CB catalyst exhibits superior ORR performance relative to t-Mn-800/CB and t-Co-800/CB with different metal centers, indicating that the intrinsic ORR activity originates from single Fe sites. The remarkable ORR properties are mainly attributed to the enhanced intrinsic activity and density of Fe active sites, as well as improved conductivity and mass transfer induced by the steric hindrance effect. The optimized t-Fe-800/CB catalyst also delivers impressive performance in both flexible and aqueous Zn–air batteries. This study offers a new perspective for the development of advanced SAC electrocatalysts for energy conversion applications.