Transforming electrochemical hydrogen Production: Tannic Acid-Boosted CoNi alloy integration with Multi-Walled carbon nanotubes for advanced bifunctional catalysis

The dimensions of alloy nanoparticles or nanosheets have emerged as a critical determinant for their prowess as outstanding electrocatalysts in water decomposition. Remarkably, the reduction in nanoparticle size results in an expanded active specific surface area, elevating reaction kinetics and showcasing groundbreaking potential. In a significant leap towards innovation, we introduced tannic acid (TA) to modify multi-walled carbon nanotubes (MWCNTs) and CoNi alloys. This ingenious strategy not only finely tuned the size of CoNi alloys but also securely anchored them to the MWCNTs substrate. The resulting synergistic "carbon transportation network" accelerated electron transfer during the reaction, markedly enhancing efficiency. Furthermore, the exceptional synergy of Co and Ni elements establishes Co0.84Ni1.69/MWCNTs as highly efficient electrocatalysts. Experimental findings unequivocally demonstrate that TA-Co0.84Ni1.69/MWCNTs require minimal overpotentials of 171 and 294 mV to achieve a current density of ± 10 mA cm-2. Serving as both anode and cathode for overall water splitting, TA-Co0.84Ni1.69/MWCNTs demand a low voltage of 1.66 V at 10 mA cm-2, maintaining structural integrity throughout extensive cyclic stability testing. These results propel TA-Co0.84Ni1.69/MWCNTs as promising candidates for future electrocatalytic advancements.

How gamified cooperation and competition motivate low-carbon actions: An investigation of gamification in a popular online payment platform in China

Climate change caused by excessive carbon emission has become one of the most severe problems facing the world's ecosystems and human society. Promoting low-carbon actions is an effective means of alleviating climate problems. Gamified interactions have recently emerged as a promising and practical idea to promote low-carbon actions; however, research on the effect of gamification design on consumers' pro-environmental behavior is still at a nascent stage. This study tried to explore the impact mechanisms of two common gamified interactions, competition and cooperation, on consumers' low-carbon actions through goal-framing theory. The proposed hypotheses were tested using a structural equation model based on survey data collected from Ant Forest users on Alipay, one of the popular online payment platforms in China. The results show that while both cooperative and competitive interactions could promote users' low-carbon actions, the incentive effect of cooperation was more significant. In addition, cooperative interactions stimulated users' normative, hedonic, and gain motivations to adopt low-carbon actions, whereas competitive interactions only motivated hedonic and gain goals. The study findings provide new insights into the role of gamification in influencing low-carbon behaviors and offer practical guidance for the design of gamification for related green and low-carbon platforms.

Microbial mutualism promoting the coexistence of competing species: Double-layer model for two competing hosts and one microbial species

Gause's law of competitive exclusion holds that the coexistence of competing species is extremely unlikely when niches are not differentiated. This law is supported by many mathematical studies, yet the coexistence of competing species is nearly ubiquitous in real ecosystems. We pay attention to the fact that plants and animals usually contact with microbial species as mutualistic partners. The activity spaces of host species are different from those of micro-organisms. In the present study, we apply double-layer model to the association of two competing hosts and a microorganism. Two lattices are prepared: one is for hosts, and the other is for microorganism. The basic equation obtained by mean-field theory is an extension of Lotka-Volterra competition model. Both mathematical analysis and numerical simulations reveal that a shared microbial mutualist can permit the coexistence of competing hosts. From the derived condition of coexistence, we believe the microbial mutualism promotes biodiversity in many ecological systems.

Identification, interactions, nitrogen removal pathways and performances of culturable heterotrophic nitrification-aerobic denitrification bacteria from mariculture water by using cell culture and metagenomics

The rapid expansion of aquaculture industry brings about significant environmental concerns, especially nitrogen pollution. Compared to nitrogen bioconversion implemented by the conventional autotrophic nitrifiers and anaerobic denitrifiers, bacteria capable of heterotrophic nitrification-aerobic denitrification (HNAD) in mariculture environments have yet to be well understood. In this study, twenty-five species of new halophilic HNAD bacteria were isolated and identified from mariculture water. By these strains co-cultured in the synthetic mariculture water (ammonia: 5 mg/L, C/N: 5, salinity: 30‰), microbial dynamic analysis showed that ammonia were mainly removed by dominant genera of Marinomonas, Marinobacterium, Halomonas, and Cobetia which simultaneously had positive correlations to total nitrogen removal. Metagenomic annotations revealed that inorganic-N was converted into gaseous-N and organic-N by these HNAD bacteria through nitrogen metabolism pathways of assimilation, partial nitrification, nitroalkane oxidation, nitrate/nitrite dissimilation reduction, and denitrification. Among them, due to the interspecific coexistence and cooperation, Marinomonas communis &Halomonas titanicae, Marinomonas communis &Cobetia marina, Marinomonas aquimarina &Halomonas titanicae, and Marinomonas aquimarina &Cobetia marina exhibited significantly better inorganic-N removal efficiency and stability. The four novel bacterial consortia could transform approximately 60% of initial ammonia into intracellular organic-N (18-20%) and gaseous-N (36-38%), which were significantly higher than those of their single strains. These findings will contribute to understanding and developing the culturable HNAD bacteria as promising candidates for nitrogen pollution control and water bioremediation in mariculture or other saline environments.

Molecular wiring of glucose oxidase enzyme with Mn polypyridine complex on MWCNT modified electrode surface and its bio-electrocatalytic oxidation and glucose sensing

A simple method for molecular wiring of glucose oxidase (GOx) enzyme with a low cost Mn polypyridine complex, Mn(phen)₂Cl₂, carboxylic acid functionalized multiwalled carbon nanotube (f-MWCNT) and Nafion (Nf), which is useful for glucose oxidation and sensing application in pH 7 phosphate buffer solution, has been demonstrated. In the typical preparation, f-MWCNT, Mn(phen)₂Cl₂, Nafion and GOx solution/suspension were successfully drop-casted as layer-by-layer on a cleaned glassy carbon electrode and potential cycled using cylic voltametric (CV) technique. In this preparation procedure, the Mn(phen)₂Cl₂ complex is in-situ converted as a dimer complex, Mn₂(phen)₂(O)(Cl₂). A cooperative interaction based on π-π, covalent, ionic, hydrophilic and hydrophobic are operated in the bioelectrode for molecular wiring and electron-transfer shutting reaction. The modified electrode is designated as GCE/f-MWCNT@Mn₂(phen)₂(O)(Cl₂)-Nf@GOx. CV response of the bioelectrode showed a defined redox peak current signal at an apparent standard electrode potential, E^°'=0.55V vs Ag/AgCl. Upon exposure of glucose, the modified electrode showed a current linearity in a range, 0-6mM with a current sensitivity value, 349.4μAmM^-1cm^-2 by CV and a current linearity in a window, 50-550μM with a current sensitivity, 316.8μAmM^-1cm^-2 at applied biased potential, 0.65V vs Ag/AgCl by amperometric i-t methods. Obtained glucose oxidation current sensitivity values are relatively higher than Os-complex based transducer systems.

Behavioral and brain synchronization differences between expert and novice teachers when collaborating with students

Differences in behavior and neural mechanisms between expert and novice teachers when collaborating with students are poorly understood. This study investigated whether expert teachers do better in collaborating with students than novice teachers and explored the neural basis of such differences. Novice teacher and student (NT-S) dyads and expert teacher and student (ET-S) dyads were recruited to complete an interactive task consisting of a cooperation and an independent condition. During the experiment, neural activity in the prefrontal cortex of the participants was recorded with functional near-infrared spectroscopy. The results show higher accuracy for the ET-S dyads than the NT-S dyads in the cooperation condition; however, no difference was found in the independent condition. Increased interpersonal brain synchronization (IBS) was detected in the left dorsolateral prefrontal cortex of participants in ET-S dyads, but not in NT-S dyads in the cooperation condition. Moreover, an interaction effect of dyad type and conditions on IBS was observed, revealing IBS was stronger in ET-S dyads than in NT-S dyads. In ET-S dyads, IBS was positively correlated with the teachers' perspective-taking ability and accuracy. These findings suggest that expert teachers collaborate better with students than novice teachers, and IBS might be the neural marker for this difference.