Generation of efficient light-induced charge separation inside the photocatalyst is an essential factor for a high catalytic efficiency. The usual immobilization of metal or metal oxide particles on semiconductor photocatalysts offers an uncontrolled assembly of active sites during the reaction. The introduction of single metal atoms on photocatalysts can lead to extremely high atomic utilization and precise active sites. However, this approach is limited because of the lack of suitable photosensitizers for single atom immobilization. Here, we have designed photocatalytic carbon quantum dots with anchoring sites for single cobalt atoms in a defined Co–N4 structure via facile pyrolysis of vitamin B12. Carbon dots functioned as both light-harvesting antenna and support for the cobalt atom with high atom loadings up to 3.27 wt %. This new photocatalytic material demonstrated enhanced visible light absorption, efficient charge separation, and reduced electrochemical impedance, while single Co atoms acted as the active site with strong oxidative ability. As a result, the photocatalysts showed excellent visible light-promoted photocatalytic efficiency with oxygen evolution rates up to 168 μmol h–1 g–1 via water oxidation, imine formation with high conversion (∼90%) and selectivity (>99%), and complete photodegradation of organic dyes.

Selective activation of photocatalysts under constant light conditions has recently been targeted to produce multiresponsive systems.H owever,c ontrolled activation, with easy recovery of the photocatalysts,i nduced by external stimuli remains am ajor challenge.M imicking the responsiveness of biological systems to multiple triggers can offer ap romising solution. Herein, we report dual-responsive polymer photocatalysts in the form of nanogels consisting of ac ross-linked poly-N-isopropylacrylamide nanogel, copolymerised with ap hotocatalytically active monomer.T he dual-responsive polymer nanogels undergo as tark decrease in diameter with increasing temperature,w hich shields the photocatalytic sites, decreasing the activity.T emperature-dependent photocatalytic formation of NAD + in water demonstrates the ability to switch photocatalysis on and off.M oreover,t he photocatalysed syntheses of several fine chemicals were carried out to demonstrate the utility of the designed material.

The polyphagous Drosophila suzukii is a highly invasive species that causes extensive damage to a wide range of berry and stone fruit crops. A better understanding of its biology and especially its behaviour will aid the development of new control strategies. We investigated the locomotor behaviour of D. suzukii in a semi-natural environment resembling a typical summer in northern England and show that adult female D. suzukii are at least 4-fold more active during daylight hours than adult males. This result was reproduced in several laboratory environments and was shown to be a robust feature of mated, but not virgin, female flies. Both males and virgin females kept on a 12 h light:12 h dark (12LD) cycle and constant temperature displayed night-time inactivity (sleep) followed by weak activity in the morning, an afternoon period of quiescence (siesta) and then a prominent evening peak of activity. Both the siesta and the sharp evening peak at lights off were severely reduced in females after mating. Flies of either sex entrained in 12LD displayed a circadian pattern of activity in constant darkness confirming the importance of an endogenous clock in regulating adult activity. This response of females to mating is similar to that elicited in female Drosophila melanogaster by the male sex peptide (SP). We used mass spectrometry to identify a molecular ion (m/z, 5145) corresponding to the poly-hydroxylated SP of D. suzukii and to show that this molecule is transferred to the female reproductive tract during copulation. We propose that the siesta experienced by male and virgin female D. suzukii is an adaptation to avoid unnecessary exposure to the afternoon sun, but that mated females faced with the challenge of obtaining resources for egg production and finding oviposition sites take greater risks, and we suggest that the change in female behaviour is induced by the male SP.

Photocatalysis has emerged as a powerful synthetic tool to facilitate redox reactions with the target of creating stable and tunable photocatalytic materials. A class of recyclable photocatalytic materials has emerged through the combination of classical polymers with photocatalytic small molecules. Classical polymers are inexpensive and easy to produce. They can be used to create cheap, easily recyclable, and reusable materials. Moreover, these materials can be imparted with a broad range of functionality and physical features, allowing the materials properties to be easily tuned according to the application requirements. The inclusion of a photocatalytic moiety enables the material to be used for a vast number of visible-light-mediated photoredox reactions. A broad range of different classical polymer architectures have been reported over the last few decades. In this Review, we will summarize the recent development of this emerging class of metal-free and heterogeneous photocatalytic platform. We will particularly discuss the inclusion of photoactive components into different polymer structures by paying attention to the synthesis route, material properties, and photoactivity of the polymeric materials produced.

Efficient heterogeneous and metal-free photocatalysts have recently been targeted as reusable materials for pollutant remediation. However, poor light penetration into photocatalytic materials currently limits modern photocatalytic systems due to uneven performance across the photocatalytic material and inefficient light usage. Here, we present a classical photocatalytic polymer hydrogel composed of a high transmittance polymer network and small conjugated photocatalytic moieties. Radical copolymerization of a photocatalytically active benzothiadiazole acrylamide monomer with water-compatible N,N-dimethylacrylamide produced a photocatalytic hydrogel where only the photocatalytic moiety absorbs visible light. The photocatalytic hydrogel network enables easy partitioning of pollutants into the gel network, where they are photocatalytically degraded. The versatility and reusability of the photocatalytic material were demonstrated for degradation of both inorganic metal and organic contaminants, including N-(phosphonomethyl)­glycine (glyphosate), the most commonly used herbicide. Furthermore, the potential of this material was explored in large-scale experiments, where glyphosate could be readily photodegraded at a half liter scale.