A novel material of Ag₃PO₄–Ag–Bi₂WO₆ Z-scheme heterojunction has been successfully synthesised using a simple deposition–precipitation method. In this work, the authors used diverse techniques to characterise the structure, catalytic performance, and morphology of the prepared materials. Meanwhile, the catalytic performance of prepared materials was evaluated by degrading organic pigment. The excellent catalytic performance of the material is according to the collaboration of Ag nanoparticles in the Ag₃PO₄–Ag–Bi₂WO₆ heterojunction. Ag nanoparticles enhance the stableness and activeness of the catalyst by acting as a charge transfer bridge between Ag₃PO₄ and Bi₂WO₆, which results in improving electron–hole pairs’ separation. Compared with pure Bi₂WO₆ and Ag₃PO₄–Bi₂WO₆ materials, Ag₃PO₄–Ag–Bi₂WO₆ has higher decomposition effectiveness of methylene blue under the same conditions. The photocatalytic mechanism was put forward and the process of the hole–electron pair's separation is discussed in detail, which is due to the formation of the Z-scheme heterojunction with Ag nanoparticles acted as a charge transfer bridge.

Glassy carbon electrode (GCE) modified with aluminium hydroxide/iron hydroxide/multi-walled carbon nanotubes (AH/IH/MWCNTs) composites has been prepared by a simple method and applied for dihydro-nicotinamide adenine dinucleotide (NADH) detection. AH/IH can not only accelerate electron transfer but also electrostatically interact with the phosphate groups of NADH through iron hydroxide to improve the sensitivity of the sensor. Meanwhile, MWCNTs served as a bonding agent to provide a built-in conductor, which resulted in boosted electron transfer at the interface. Compared with the GCE, MWCNTs–GCE, and AH/MWCNTs–GCE, the AH/IH/MWCNTs–GCE exhibited an extraordinary electrocatalytic response towards NADH, with a wide linear concentration range from 0.5 to 220 μM with a low-detection limit of 0.30 μM, at a comparatively low potential (+0.15 V versus Ag/AgCl). Moreover, alcohol dehydrogenase was used as a model system for the design of a sensitive ethanol biosensor. The resulting biosensor exhibited an ethanol sensitivity of 9 μA/mM, a concentration range of 20–400 μM, and a detection limit of 5 μM. These results demonstrate the potential of the AH/IH/MWCNTs nanocomposite film for biosensors in combination with NADH-producing enzymes.

Biocatalysis has the potential to enable green chemistry. New methods of enzyme immobilisation will be required to improve enzyme stability, product purification, and compatibility of different enzymes in the same reaction conditions. Deoxyribonucleic acid (DNA) stands out among supramolecular scaffolds, as simple Watson–Crick base-pairing rules can be used to rationally design a unique nanoscale environment around each individual enzyme in a cascade. Enhancements of enzyme activity and stability on DNA nanostructures have previously been reported, but never in the context of industrially relevant chemical syntheses or reaction conditions. Here, the authors show DNA can enhance the activity and stability of a galactose oxidase mutant, which could be used in a cascade to produce bioplastics from lignin. The enzyme was enhanced in the cell-free extract, which to their knowledge has not been shown before for any enzymes on DNA. This is significant because crude biocatalytic reactions are vastly more cost-effective. This opens the door to further work on multienzyme cascades by tuning the properties of individual enzymes.

The flower-like and hexagonal flake-like ZnO microstructures were synthesised by a microwave method using ammonia water and sodium hydroxide as precipitant, respectively. The products were characterised by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction and photoluminescence. The photocatalytic activity of the flower-like and hexagonal flake-like ZnO microstructures was evaluated by the degradation of methyl orange (MO) under ultraviolet (UV) light irradiation. The results indicated that the best flower-like ZnO microstructure was obtained when the experimental conditions were [Zn²⁺] = 0.025 mol l⁻¹, [Zn²⁺]:[NH₃·H₂O] = 1:1.5, microwave power = 231 W. Under the same reaction conditions, hexagonal flake-like ZnO can be obtained by using sodium hydroxide as precipitant. The MO in aqueous solution was completely eliminated by flower-like ZnO after 120 min of UV light irradiation. Under identical conditions, the degradation of MO in aqueous solution was completely finished within 150 min in the presence of hexagonal flake-like ZnO. The flower-like ZnO sample showed an enhanced photocatalytic activity compared with the hexagonal flake-like ZnO for the MO degradation, which could be attributed to the presence of more active centres and hence can have more opportunities to contact with MO molecules.

In this study, a typical MXene material, Ti₃C₂, was selected as a co-catalyst and then integrated with ZnO via a facile hydrothermal strategy. The phase composition, morphology, and photophysical properties of as-prepared samples were investigated by XRD, field emission SEM, ultraviolet–visible spectrophotometer, and fluorescence spectrophotometer, respectively. In addition, the results of the photocatalysis experiment showed that the photocatalytic activity of ZnO can be improved significantly through the hybridisation with Ti₃C₂, which arises from the inhibition of the photogenerated carriers recombination. Furthermore, the theoretical analysis indicated that the high-quantum efficiency arises from the appropriate Fermi level position of Ti₃C₂. This work demonstrated that Ti₃C₂ will show great potential for constructing novel and efficient photocatalysts.

To investigate the influence of graphene on the photocatalytic activity of bismuth ferrite (BiFeO₃), BiFeO₃ and flaky BiFeO₃@graphene were prepared through the hydrothermal-synthesis process. The as-prepared particles were characterised by XRD, TGA, SEM, X-ray photoelectron spectroscopy, and PL measurements. The results show that the BiFeO₃ nanoparticles have a microstructure and homogeneously attached to graphene sheets. Moreover, the flaky BiFeO₃@graphene composites exhibited higher photocatalytic efficiency than pure BiFeO₃, especially under visible light irradiation. The synergistic effects of graphene and BiFeO₃ of composites were proposed to guide the further improvement of their photocatalytic activity.

Pectin-conjugated CdS/ZnS core/shell nanocrystals were prepared by using a microwave-assisted approach without the addition of any external ligands. The prepared cubic phase CdS/ZnS nanocrystals were uniform and mono-dispersed with sizes of 6–9 nm. The charge and long-chain structure of pectin molecules effectively prevented the aggregation of CdS/ZnS nanocrystals. In addition, pectin molecules have multiple functional groups, such as O–H, C=O, and COO⁻, which could conjugate with the surface of samples to control the growth of CdS/ZnS nanocrystals. Thermogravimetric analysis provided evidence that the obtained products are inorganic–organic hybrid materials. Based on the analysis of ultraviolet–visible spectra, it was found that the formation of ZnS shell led to a red-shift and an enhancement of absorption of CdS/ZnS nanocrystals compared with that of CdS. Photocatalytic activity of CdS/ZnS nanocrystals was monitored by the degradation of Rhodamine B under visible light irradiation. The presence of ZnS shell inhibited photo-corrosion and photo-dissolution of CdS nanocatalyst, thus resulting in a significant enhancement of photocatalytic activity and stability.

In this study, copper ferrite (CuFe₂O₄) nanoparticles were successfully prepared and employed as an efficient catalyst for the synthesis of guanidine derivatives through the addition of anilines to N, N-dicyclohexylcarcodiimide under solvent-free conditions. This magnetically retrievable catalyst was well characterised by Fourier transform infrared spectroscopy, X-ray powder diffraction, transmission electron microscopy and field emission scanning electron microscope-energy dispersive X-ray techniques. The catalyst can be readily recovered from the reaction mixture by the use of an external magnet and reused several times without remarkable loss of its catalytic activity.

Gold nanoparticles (AuNPs) possess colourful light-scattering properties due to different composition, size and shape. Their unique physical, optical and chemical properties coupled with advantages, have increased the scope of anisotropic AuNPs in various fields. This study reports a green methodology developed for the synthesis of anisotropic AuNPs. The aqueous extracts of Alternanthera sessilis (PGK), Portulaca oleracea (PAK) and Sterculia foetida (SF) with gold ions produced violet, purple and pink coloured AuNPs, respectively, under sonication and room temperature methods revealing the formation of different shapes of AuNPs. The results of TEM analysis of AuNPs confirmed the formation of triangular plate AuNPs of the size 35 nm for PAK extract. Spherical-shaped AuNPs (10–20 nm) were obtained using an extract of PGK. SF extract produced rod, hexagon, pentagon-shaped AuNPs and nanorice gold particles. The cell viability studies of the PGK, PAK and SF-mediated AuNPs on MCF-7 cell lines by MTT assay revealed the cytotoxic activity of AuNPs to depend on the size, shape and the nature of capping agents. The synthesised AuNPs significantly inhibited the growth of cancer cells (MCF-7) in a concentration-dependent manner. The size and shape of these anisotropic AuNPs also reveal its potency to be used as sensors, catalysis, photothermal and therapeutic agents.

Novel triclinic bismuth oxide (ω-Bi₂O₃) microcrystals with a pyramid-like shape were successfully synthesised by a facile hydrothermal method. The effects of potassium sodium tartrate (KNaC₄H₄O₆·4H₂O) concentration and the reaction time on the morphology were investigated, respectively. The experimental results showed that the tartrate (C₄H₄O₆ ^2–) ions were responsible for the crystal growth of pyramid-like ω-Bi₂O₃ at the same reaction time. The photocatalytic activity of ω-Bi₂O₃ pyramids was evaluated by degrading methyl orange under the visible-light irradiation, revealing the ω-Bi₂O₃ pyramids exhibited outstanding photocatalytic activity due to its suitable bandgap energy.