Photoelectrochemical (PEC) water splitting is an appealing approach for “green” hydrogen generation. The natural p-type semiconductor of Cu2O is one of the most promising photocathode candidates for direct hydrogen generation. However, the Cu2O-based photocathodes still suffer severe self-photo-corrosion and fast surface electron-hole recombination issues. Herein, we propose a facile in-situ encapsulation strategy to protect Cu2O with hydrogen-substituted graphdiyne (HsGDY) and promote water reduction performance. The HsGDY encapsulated Cu2O nanowires (HsGDY@Cu2O NWs) photocathode demonstrates a high photocurrent density of −12.88 mA cm−2 at 0 V versus the reversible hydrogen electrode under 1 sun illumination, approaching to the theoretical value of Cu2O. The HsGDY@Cu2O NWs photocathode as well as presents excellent stability and contributes an impressive hydrogen generation rate of 218.2 ± 11.3 μmol h−1cm−2, which value has been further magnified to 861.1 ± 24.8 μmol h−1cm−2 under illumination of concentrated solar light. The in-situ encapsulation strategy opens an avenue for rational design photocathodes for efficient and stable PEC water reduction.

Long-term in vivo monitoring and tracking of target molecules in living organism is essential to reveal vital physiological activity. However, undesirable contamination of protein and biological cells may bring serious biofouling issues. Herein, zwitterionic sulfobetaine methacrylate (SBMA) polymers are grafted on the TiO2 nanotube (NT) surface with polydopamine (PDA) as linker to fabricate a TiO2 NTs/PDA/SBMA photoelectrode. The TiO2 NTs/PDA/SBMA/aptamer-based PEC aptasensor can be sensitive and have selective detection of target molecules with excellent antibiofouling activity. Beneficial from the above advantages, the implantable micro-PEC aptasensor has implemented in vivo tracking and monitoring of the metabolism of antibiotics in a living mouse. The robust antibiofouling property generates new inquiries and an approach for long-standing questions in a new way for reliable and long-term sensing of vital biomolecules in complex biological fluids and uncovers a promising advance of intrinsic physiological mechanisms.

A hyphenated strategy for photoelectrochemical (PEC) disinfection is proposed with rationally designed black TiO2–x as a photoresponsive material. The PEC method, a fusion of electrochemistry and photocatalysis, is an innovative and effective way to improve photocatalytic performance, which imparts certain properties to the photoelectrode and greatly promotes the charge transfer, thus effectively inhibiting the recombination of carriers and greatly promoting the catalytic efficiency. The oxygen vacancy (V o) engineering on TiO2 is conducted to obtain black TiO2–x , which shows a much larger light absorption region in the full solar spectrum than the pristine white TiO2 and presents excellent PEC sterilization performance. The bactericidal efficiency with the PEC method is 10 times higher than that with the photocatalytic method, inactivating 99% of bacteria within a short time of 30 min. In addition, the black titanium oxide nanowires (B-TiO2–x NWs) are grown on flexible carbon cloth (CC) to form a sandwich structural self-cleaning face mask. The bacteria adhering to the surface of the mask will be sterilized quickly and efficiently under the illumination of visible light. The face mask with the characteristics of superior antibacterial effect and long service lifetime will be used for epidemic prevention and reduce the second pollution.

Interface engineering is a promising strategy to optimize interfacial photoelectrochemical (PEC) water splitting system. However, most previous attentions are paid on engineering of semiconductor/water interface, another essential interface of electrode/current...

The real-time detection of nitric oxide (NO) in living cells is essential to reveal its physiological processes. However, the popular electrochemical detection strategy is limited to the utilization of noble metals. The development of new detection candidates without noble metal species still maintaining excellent catalytic performance has become a big challenge. Herein, we propose a spinel oxide doped with heteroatom-Cu-doped Co3O4 (Cu-Co3O4) for the sensitive and selective detection of NO release from the living cells. The material is strategically designed with Cu occupying the tetrahedral (T d) center of Co3O4 through the formation of a Cu–O bond. The introduced Cu regulates the local coordination environment and optimizes the electronic structure of Co3O4, hybridizing with the N 2p orbital to enhance charge transfer. The Cu Td site can well inhibit the current response to nitrite (NO2 –), resulting in a high improvement in the electrochemical oxidation of NO. The selectivity of Cu-Co3O4 can be markedly improved by the pore size of the molecular sieve and the negative charge on the surface. The rapid transmission of electrons is due to the fact that Cu-Co3O4 can be uniformly and densely in situ grown on Ti foil. The rationally designed Cu-Co3O4 sensor displays excellent catalytic activity toward NO oxidation with a low limit of detection of 2.0 nM (S/N = 3) and high sensitivity of 1.9 μA nM–1 cm–2 in cell culture medium. The Cu-Co3O4 sensor also shows good biocompatibility to monitor the real-time NO release from living cells (human umbilical vein endothelial cells: HUVECs; macrophage: RAW 264.7 cells). It was found that a remarkable response to NO was obtained in different living cells when stimulated by l-arginine (l-Arg). Moreover, the developed biosensor could be used for real-time monitoring of NO released from macrophages polarized to a M1/M2 phenotype. This cheap and convenient doping strategy shows universality and can be used for sensor design of other Cu-doped transition metal materials. The Cu-Co3O4 sensor presents an excellent example through the design of proper materials to implement unique sensing requirements and sheds light on the promising strategy for electrochemical sensor fabrication.