You can find a review of interesting research topics in the following article:

Article Internet of Things (IoT): A Review of Enabling Technologies,...

You can control your house hold appliances through your IOT project.

Dear Kevin Fajar Riyadi,

the following topic might be interesting for you:

Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis of selected IoT services

Here are some sources about the importance of SWOT analysis in the use of IoT services

Best regards and much success

Anatol Badach

https://sites.google.com/site/cis4397ts/home/module4hw/porter-iot-swot-analysis

http://theiotportal.com/2015/07/01/swot-analysis-of-the-internet-of-things/

https://creately.com/diagram/example/iqxlksqt1/SWOT%20Analysis%20IoT

http://fernfortuniversity.com/term-papers/swot/nyse/4400-iot-group-limited.php

https://pestleanalysis.com/swot-analysis-of-the-internet-of-things/

https://www.ausy.be/en/blog/swot-analysis-iot-and-antwerp-smart-city

Mihai DOINEA, Cătălin BOJA, Lorena BATAGAN, Cristian TOMA, Marius POPA: Internet of Things Based Systems for Food Safety Management

http://revistaie.ase.ro/content/73/08%20-%20Doinea,%20Boja,%20Batagan,%20Toma,%20Popa.pdf

Future developments in cyber risk assessment for the internet of things

https://mpra.ub.uni-muenchen.de/92567/1/MPRA_paper_92567.pdf

If you want a more specific topic, try the following : Routing environmental data using mobile IoT devices.

Here are some ideas about IoT

Chapter IoT-Based Framework for Crowd Management

Poster INTEGRATING LEGACY METERING INFRASTRUCTURE INTO SMART METERING SYSTEMS

Maybe you can look into:

1. IoT-based supply-chain management

2. IoT-based logistics

I suggest you to target for Industry 4.0

https://www.researchgate.net/publication/336375422_The_Internet_of_Things_IoT_a_survey_of_techniques_operating_systems_and_trends