9.3.5 Atomic structure engineering by using focused ion beams -- 9.3.6 Irradiation tolerance -- 9.4 Applications -- 9.5 Summary, challenges, and outlook -- Acknowledgments -- References -- 10 Tailoring defects in 2D materials for electrocatalysis -- 10.1 Introduction -- 10.2 Defect-tailored 2D electrocatalysts for hydrogen evolution reaction (HER) -- 10.2.1 Fundamental principles of electrocatalytic HER -- 10.2.2 Catalytic activity descriptors of electrocatalytic HER -- 10.2.3 Defect-tailored 2D electrocatalysts for HER -- 10.3 Defect-tailored 2D electrocatalysts for oxygen evolution reaction (OER) -- 10.3.1 Fundamental principles of electrocatalytic OER -- 10.3.2 Catalytic activity descriptors of electrocatalytic OER -- 10.3.3 Defect-tailored 2D electrocatalysts for OER -- 10.4 Defect-tailored 2D electrocatalysts for nitrogen reduction reaction (NRR) -- 10.4.1 Fundamental principles of electrocatalytic NRR -- 10.4.2 Catalytic activity descriptors of electrocatalytic NRR -- 10.4.3 Defect-tailored 2D electrocatalysts for NRR -- 10.5 Defect-tailored 2D electrocatalysts for carbon dioxide reduction reaction (CO2RR) -- 10.5.1 Fundamental principles of electrocatalytic CO2RR -- 10.5.2 Catalytic activity descriptors of electrocatalytic CO2RR -- 10.5.3 Defect-tailored 2D electrocatalysts for CO2RR -- 10.6 Challenges and perspectives of defect engineering for 2D electrocatalysts -- Acknowledgments -- References -- 11 Devices and defects in two-dimensional materials: outlook and perspectives -- 11.1 Introduction -- 11.2 Defect characterization in 2D TMDs using ultrafast pump-probe spectroscopy -- 11.2.1 Motivation -- 11.2.2 Pump-probe spectroscopy -- 11.2.3 Point defects -- 11.2.4 Edges/grain boundaries -- 11.3 Devices fabricated on 2D CVD-grown TMDs -- 11.3.1 Effect of top gate dielectrics -- 11.3.1.1 Al2O3 -- 11.3.1.2 HfO2 -- 11.3.1.3 ZrO2.