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Graphene (G) films were grown on copper foils by chemical vapor deposition and transferred onto n-type silicon (Si) to form G/Si Schottky heterojunction solar cells. The power conversion efficiencies (PCEs) of the G/Si solar cells were in the range of 1.94-2.66%. Four volatile oxidants HNO 3 , HCl, H 2 O 2 and SOCl 2 were employed to treat the graphene films in the G/Si solar cells, and the PCEs could be greatly enhanced after being treated by all the volatile oxidants and SOCl 2 doping showed the best improvement. A solar cell with an initial PCE of 2.45% could be increased to 5.95% upon SOCl 2 doping treatment. The PCE stability of the volatile oxidant-treated cells was also investigated. The PCEs decreased with time, while SOCl 2 and HCl showed much better PCE stability than HNO 3 and H 2 O 2 .

Ultrasensitive pressure sensors are constructed with few-layer MoS films. As-designed Fabry-Perot (F-P) sensors exhibit nearly synchronous pressure-deflection responses with a very high sensitivity (89.3 nm Pa ), which is three orders of magnitude higher than those of conventional diaphragm materials (e.g., silica, silver films). This kind of F-P sensor may open up new avenues for 2D materials in biomedical and environmental applications.

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Combining self‐healing functions with damage diagnosing, which can achieve timely healing autonomously, is expected to improve the reliability and reduce life cycle cost of materials. Here, a flexible conductive composite composed of a dynamically crosslinked polyurethane bearing Diels–Alder bonds (PUDA) and carbon nanotubes (CNTs), which possess both crack diagnosing and self‐healing functions, is reported. The introduced dynamic Diels–Alder bonds endow the materials self‐healing function and the powder‐based preparation route based on the specially designed CNTs‐coated PUDA micropowders leads to the formation of segregated CNTs network, which makes the composite possess excellent mechanical properties and high conductivity. Because of the sufficient electrothermal and photothermal effect of CNTs, the composites can be healed rapidly and repeatedly by electricity or near‐infrared light based on the retro‐Diels–Alder reaction. An obvious color difference in the infrared thermograph resulting from the resistance difference between damaged and undamaged area can be observed when applying the voltage, which can be used for crack diagnosing. Using the same electrical circuit, the crack in the PUDA/CNTs composite can be noninvasively detected first and then be autonomously healed. The composites also exhibit a strain‐sensing function with good sensitivity and high reliability, thus will have potential applications in electronic strain sensors.

Selective laser sintering (SLS), which can directly turn 3D models into real objects, is employed to prepare the flexible thermoplastic polyurethane (TPU) conductor using self‐made carbon nanotubes (CNTs) wrapped TPU powders. The SLS printing, as a shear‐free and free‐flowing processing without compacting, provides a unique approach to construct conductive segregated networks of CNTs in the polymer matrix. The electrical conductivity for the SLS processed TPU/CNTs composite has a lower percolation threshold of 0.2 wt% and reaches ≈10−1 S m−1 at 1 wt% CNTs content, which is seven orders of magnitude higher than that of conventional injection‐molded TPU/CNTs composites at the same CNTs content. The 3D printed TPU/CNTs specimen can maintain good flexibility and durability, even after repeated bending for 1000 cycles, the electrical resistance can keep at a nearly constant value. The flexible conductive TPU/CNTs composite with complicated structures and shapes like porous piezoresistors can be easily obtained by this approach.

The photovoltaic effect of titanium dioxide (TiO2) nanoparticles, induced by ultraviolet light, can greatly improve the catalytic activity of hemoglobin as a peroxidase, with the sensitivity increased nearly 3-fold and the detection limit lowered 2 orders, in contrast to the catalytic reactions in the dark, which indicates a possible method to tune the properties of proteins for development of photocontrolled protein-based biosensors.

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