The construction of heterojunctions provides a promising strategy to improve photocatalytic hydrogen evolution. However, how to fabricate a nanoscale TiO₂/g-C₃N₄ heterostructure and hinder the aggregation of bulk g-C₃N₄ using simple methods remains a challenge. In this work, we use a simple in situ construction method to design a heterojunction model based on molecular self-assembly, which uses a small molecule matrix for self-integration, including coordination donors (AgNO₃), inorganic titanium source (Ti(SO₄)₂) and g-C₃N₄ precursor (melamine). The self-assembled porous g-C₃N₄ nanotube can hamper carrier aggregation and it provides numerous catalytic active sites, mainly via the coordination of Ag⁺ ions. Meanwhile, the TiO₂ NPs are easily mineralized on the nanotube template in dispersive distribution to form a heterostructure via an N–Ti bond of protonation, which contributes to shortening the interfacial carrier transport, resulting in enhanced electron-hole pairs separation. Originating from all of the above synergistic effects, the obtained Ag/TiO₂/g-C₃N₄ heterogenous photocatalysts exhibit an enhanced H₂ evolution rate with excellent sustainability 20.6-fold-over pure g-C₃N₄. Our report provides a feasible and simple strategy to fabricate a nanoscale heterojunction incorporating g-C₃N₄, and has great potential in environmental protection and water splitting.

Nano-sized palladium nanoparticles showed high catalytic activity with severe limitations in catalytic field due to the tendency to aggregate. A solid substrate with large specific surface area is an ideal carrier for palladium nanoparticles. In present work, polyethyleneimine/polycaprolactone/Pd nanoparticles (PEI/PCL@PdNPs) composite catalysts were successfully designed and prepared by electrospinning and reduction methods using PEI/PCL elexctrospun fiber as carrier. The added PEI component effectively regulated the microscopic morphology of the PEI/PCL fibers, following a large number of pit structures which increased the specific surface area of the electrospun fibers and provided active sites for loading of the palladium particles. The obtained PEI/PCL@PdNPs catalysts for reductions of 4-nitrophenol (4-NP) and 2-nitroaniline (2-NA) exhibited extremely efficient, stable, and reusable catalytic performance. It was worth mentioning that the reaction rate constant of catalytic reduction of 4-NP was as high as 0.16597 s⁻¹. Therefore, we have developed a highly efficient catalyst with potential applications in the field of catalysis and water treatment.

With development of the society, the problem of environmental pollution is becoming more and more serious. There is the urgent need to develop a new type of sustainable green material for degradable pollutants. However, the conventional preparation method is limited by conditions such as cumbersome operation, high energy consumption, and high pollution. Here, a simple method named self-reduction has been proposed, to synthesize highly efficient catalytic nitro compounds and morin self-assembled MXene-Pd nanocomposites. Palladium nanoparticles were grown in situ on MXene nanosheets to form MXene@PdNPs. MXene@PdNPs composites with different reaction times were prepared by adjusting the reduction reaction time. In particular, MXene@PdNPs20 exhibited a high catalytic effect on 4-NP and 2-NA, and the first-order rate constants of the catalysis were 0.180 s⁻¹ and 0.089 s⁻¹, respectively. It should be noted that after eight consecutive catalytic cycles, the conversion to catalyze 4-NP was still greater than 94%, and the conversion to catalyze 2-NA was still greater than 91.8%. Therefore, the research of self-assembled MXene@PdNPs nanocomposites has important potential value for environmental management and sustainable development of human health, and provides new clues for the future research of MXene-based new catalyst materials.

With the rapid development of industry, the problem of environmental pollution has become increasingly prominent. Exploring and preparing green, efficient, and low cost catalysts has become the key challenge for scientists. However, some conventional preparation methods are limited by conditions, such as cumbersome operation, high energy consumption, and high pollution. Here, a simple and efficient seed-mediated method was designed and proposed to synthesize a highly efficient bimetallic catalyst for catalyzing nitro compounds. A Pd-Cu bimetallic composite (BCM) can be prepared by synthesizing the original seed crystal of precious metal palladium, then growing the mature nanocrystalline palladium and supporting the transition metal copper. Importantly, after eight consecutive catalytic cycles, the conversion of the catalyzed 2-NA was 84%, while the conversion of the catalyzed 4-NP was still 72%. And the catalytic first order rates of 2-NA and 4-NP constants were 0.015 s⁻¹, and 0.069 s⁻¹, respectively. Therefore, current research of nanocomposites catalyst showed great significance for serious environmental pollution problems and the protection of living environment, providing a new idea for the preparation of new bimetallic catalytic materials.

Addressing the challenge of roll loss and strip deformation arising from the lack of precise prediction of the roll temperature field in hot tandem rolling mills, this study employs numerical analysis via the finite difference method. Based on the roll temperature field and hot roll crown model, an intelligent support cooling control system for the roll cooling water of hot rolls is established. This system comprehensively considers the direct impact of specific parameters on the roll temperature field in the intricate context of cooling water dynamics. The study focuses on the cyclic superposition effect of rolling coil quantities on the roll temperature field and the resulting hot roll shape, and theoretical calculations along with simulation analyses were conducted using finite element software. Through the integration of field-measured values, the study achieves accurate predictions of the temperature field and hot roll profile for both work rolls and backup rolls.

This study has fully considered the mechanical and technological characteristics of a continuous annealing and processing line (CAPL) by proposing the concept of in section shape and out section shape, building a set of in section shape and out section shape prediction models, and quantitatively analysing the differences between them. The paper provides a set of comprehensive control models suitable for CAPL, targeting the best overall section shape, the minimum in section shape and the minimum shape difference between unit exit and the goal; develops a set of online prediction and control software for cold rolling strip shape in CAPL and promotes it in practical production to improve the strip conveying stability and accuracy of exit shape control.